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  • Crystallography, X-Ray  (342)
  • Nature Publishing Group (NPG)  (342)
  • 2010-2014  (342)
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  • 1
    Publication Date: 2010-10-15
    Description: The pre-T-cell antigen receptor (pre-TCR), expressed by immature thymocytes, has a pivotal role in early T-cell development, including TCR beta-selection, survival and proliferation of CD4(-)CD8(-) double-negative thymocytes, and subsequent alphabeta T-cell lineage differentiation. Whereas alphabetaTCR ligation by the peptide-loaded major histocompatibility complex initiates T-cell signalling, pre-TCR-induced signalling occurs by means of a ligand-independent dimerization event. The pre-TCR comprises an invariant alpha-chain (pre-Talpha) that pairs with any TCR beta-chain (TCRbeta) following successful TCR beta-gene rearrangement. Here we provide the basis of pre-Talpha-TCRbeta assembly and pre-TCR dimerization. The pre-Talpha chain comprised a single immunoglobulin-like domain that is structurally distinct from the constant (C) domain of the TCR alpha-chain; nevertheless, the mode of association between pre-Talpha and TCRbeta mirrored that mediated by the Calpha-Cbeta domains of the alphabetaTCR. The pre-TCR had a propensity to dimerize in solution, and the molecular envelope of the pre-TCR dimer correlated well with the observed head-to-tail pre-TCR dimer. This mode of pre-TCR dimerization enabled the pre-Talpha domain to interact with the variable (V) beta domain through residues that are highly conserved across the Vbeta and joining (J) beta gene families, thus mimicking the interactions at the core of the alphabetaTCR's Valpha-Vbeta interface. Disruption of this pre-Talpha-Vbeta dimer interface abrogated pre-TCR dimerization in solution and impaired pre-TCR expression on the cell surface. Accordingly, we provide a mechanism of pre-TCR self-association that allows the pre-Talpha chain to simultaneously 'sample' the correct folding of both the V and C domains of any TCR beta-chain, regardless of its ultimate specificity, which represents a critical checkpoint in T-cell development. This unusual dual-chaperone-like sensing function of pre-Talpha represents a unique mechanism in nature whereby developmental quality control regulates the expression and signalling of an integral membrane receptor complex.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pang, Siew Siew -- Berry, Richard -- Chen, Zhenjun -- Kjer-Nielsen, Lars -- Perugini, Matthew A -- King, Glenn F -- Wang, Christina -- Chew, Sock Hui -- La Gruta, Nicole L -- Williams, Neal K -- Beddoe, Travis -- Tiganis, Tony -- Cowieson, Nathan P -- Godfrey, Dale I -- Purcell, Anthony W -- Wilce, Matthew C J -- McCluskey, James -- Rossjohn, Jamie -- England -- Nature. 2010 Oct 14;467(7317):844-8. doi: 10.1038/nature09448.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20944746" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallography, X-Ray ; Gene Rearrangement, T-Lymphocyte/genetics ; Humans ; Models, Molecular ; Mutation ; Protein Folding ; *Protein Multimerization ; Protein Structure, Tertiary ; Receptors, Antigen, T-Cell/*chemistry/genetics/*metabolism ; Receptors, Antigen, T-Cell, alpha-beta/chemistry/metabolism ; Signal Transduction ; Solutions ; T-Lymphocytes/cytology/immunology/metabolism
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  • 2
    Publication Date: 2010-02-19
    Description: E1 enzymes activate ubiquitin (Ub) and ubiquitin-like (Ubl) proteins in two steps by carboxy-terminal adenylation and thioester bond formation to a conserved catalytic cysteine in the E1 Cys domain. The structural basis for these intermediates remains unknown. Here we report crystal structures for human SUMO E1 in complex with SUMO adenylate and tetrahedral intermediate analogues at 2.45 and 2.6 A, respectively. These structures show that side chain contacts to ATP.Mg are released after adenylation to facilitate a 130 degree rotation of the Cys domain during thioester bond formation that is accompanied by remodelling of key structural elements including the helix that contains the E1 catalytic cysteine, the crossover and re-entry loops, and refolding of two helices that are required for adenylation. These changes displace side chains required for adenylation with side chains required for thioester bond formation. Mutational and biochemical analyses indicate these mechanisms are conserved in other E1s.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866016/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866016/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Olsen, Shaun K -- Capili, Allan D -- Lu, Xuequan -- Tan, Derek S -- Lima, Christopher D -- F32 GM075695/GM/NIGMS NIH HHS/ -- F32 GM075695-03/GM/NIGMS NIH HHS/ -- R01 AI068038/AI/NIAID NIH HHS/ -- R01 AI068038-02/AI/NIAID NIH HHS/ -- R01 AI068038-03/AI/NIAID NIH HHS/ -- R01 GM065872/GM/NIGMS NIH HHS/ -- R01 GM065872-09/GM/NIGMS NIH HHS/ -- RR-15301/RR/NCRR NIH HHS/ -- England -- Nature. 2010 Feb 18;463(7283):906-12. doi: 10.1038/nature08765.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology, Sloan-Kettering Institute, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20164921" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; *Biocatalysis ; Catalytic Domain/*physiology ; Conserved Sequence ; Crystallography, X-Ray ; Cysteine/chemistry/metabolism ; Humans ; Magnesium/metabolism ; Models, Molecular ; Molecular Sequence Data ; Protein Conformation ; SUMO-1 Protein/*chemistry/*metabolism ; Saccharomyces cerevisiae ; Saccharomyces cerevisiae Proteins/metabolism ; Small Ubiquitin-Related Modifier Proteins/metabolism ; Sulfides/*metabolism ; Ubiquitin/metabolism ; Ubiquitin-Activating Enzymes/*chemistry/*metabolism ; Ubiquitins/metabolism
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  • 3
    Publication Date: 2010-05-21
    Description: Type II topoisomerases are required for the management of DNA tangles and supercoils, and are targets of clinical antibiotics and anti-cancer agents. These enzymes catalyse the ATP-dependent passage of one DNA duplex (the transport or T-segment) through a transient, double-stranded break in another (the gate or G-segment), navigating DNA through the protein using a set of dissociable internal interfaces, or 'gates'. For more than 20 years, it has been established that a pair of dimer-related tyrosines, together with divalent cations, catalyse G-segment cleavage. Recent efforts have proposed that strand scission relies on a 'two-metal mechanism', a ubiquitous biochemical strategy that supports vital cellular processes ranging from DNA synthesis to RNA self-splicing. Here we present the structure of the DNA-binding and cleavage core of Saccharomyces cerevisiae topoisomerase II covalently linked to DNA through its active-site tyrosine at 2.5A resolution, revealing for the first time the organization of a cleavage-competent type II topoisomerase configuration. Unexpectedly, metal-soaking experiments indicate that cleavage is catalysed by a novel variation of the classic two-metal approach. Comparative analyses extend this scheme to explain how distantly-related type IA topoisomerases cleave single-stranded DNA, unifying the cleavage mechanisms for these two essential enzyme families. The structure also highlights a hitherto undiscovered allosteric relay that actuates a molecular 'trapdoor' to prevent subunit dissociation during cleavage. This connection illustrates how an indispensable chromosome-disentangling machine auto-regulates DNA breakage to prevent the aberrant formation of mutagenic and cytotoxic genomic lesions.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2882514/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2882514/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schmidt, Bryan H -- Burgin, Alex B -- Deweese, Joseph E -- Osheroff, Neil -- Berger, James M -- CA077373/CA/NCI NIH HHS/ -- GM033944/GM/NIGMS NIH HHS/ -- GM053960/GM/NIGMS NIH HHS/ -- GM08295/GM/NIGMS NIH HHS/ -- R01 CA077373/CA/NCI NIH HHS/ -- R01 CA077373-11S1/CA/NCI NIH HHS/ -- R01 CA077373-12/CA/NCI NIH HHS/ -- R01 GM033944/GM/NIGMS NIH HHS/ -- T32 CA009592/CA/NCI NIH HHS/ -- T32CA09592/CA/NCI NIH HHS/ -- England -- Nature. 2010 Jun 3;465(7298):641-4. doi: 10.1038/nature08974.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20485342" target="_blank"〉PubMed〈/a〉
    Keywords: Allosteric Regulation ; Base Sequence ; Catalytic Domain ; Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; DNA Topoisomerases, Type I/*chemistry/*metabolism ; DNA Topoisomerases, Type II/*chemistry/*metabolism ; Kinetics ; Models, Molecular ; Molecular Sequence Data ; Saccharomyces cerevisiae/*enzymology ; Tyrosine
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  • 4
    Publication Date: 2010-05-14
    Description: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883250/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883250/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Karpowich, Nathan K -- Wang, Da-Neng -- F32 HL091618-03/HL/NHLBI NIH HHS/ -- R01 DK053973/DK/NIDDK NIH HHS/ -- R01 DK053973-12/DK/NIDDK NIH HHS/ -- R01 GM093825/GM/NIGMS NIH HHS/ -- R01 GM093825-01/GM/NIGMS NIH HHS/ -- R01 MH083840/MH/NIMH NIH HHS/ -- R01 MH083840-03/MH/NIMH NIH HHS/ -- R21 GM075936/GM/NIGMS NIH HHS/ -- R21 GM075936-02/GM/NIGMS NIH HHS/ -- U54 GM075026/GM/NIGMS NIH HHS/ -- U54 GM075026-050010/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 May 13;465(7295):171-2. doi: 10.1038/465171a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20463728" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/*metabolism ; Crystallography, X-Ray ; Fluorescence Resonance Energy Transfer ; Molecular Dynamics Simulation ; Plasma Membrane Neurotransmitter Transport Proteins/*chemistry/*metabolism ; Protein Conformation ; Sodium/metabolism
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  • 5
    Publication Date: 2010-10-12
    Description: Jasmonates are a family of plant hormones that regulate plant growth, development and responses to stress. The F-box protein CORONATINE INSENSITIVE 1 (COI1) mediates jasmonate signalling by promoting hormone-dependent ubiquitylation and degradation of transcriptional repressor JAZ proteins. Despite its importance, the mechanism of jasmonate perception remains unclear. Here we present structural and pharmacological data to show that the true Arabidopsis jasmonate receptor is a complex of both COI1 and JAZ. COI1 contains an open pocket that recognizes the bioactive hormone (3R,7S)-jasmonoyl-l-isoleucine (JA-Ile) with high specificity. High-affinity hormone binding requires a bipartite JAZ degron sequence consisting of a conserved alpha-helix for COI1 docking and a loop region to trap the hormone in its binding pocket. In addition, we identify a third critical component of the jasmonate co-receptor complex, inositol pentakisphosphate, which interacts with both COI1 and JAZ adjacent to the ligand. Our results unravel the mechanism of jasmonate perception and highlight the ability of F-box proteins to evolve as multi-component signalling hubs.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2988090/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2988090/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sheard, Laura B -- Tan, Xu -- Mao, Haibin -- Withers, John -- Ben-Nissan, Gili -- Hinds, Thomas R -- Kobayashi, Yuichi -- Hsu, Fong-Fu -- Sharon, Michal -- Browse, John -- He, Sheng Yang -- Rizo, Josep -- Howe, Gregg A -- Zheng, Ning -- P30 DK056341/DK/NIDDK NIH HHS/ -- P30 DK056341-10/DK/NIDDK NIH HHS/ -- R01 AI068718/AI/NIAID NIH HHS/ -- R01 AI068718-04/AI/NIAID NIH HHS/ -- R01 CA107134/CA/NCI NIH HHS/ -- R01 CA107134-07/CA/NCI NIH HHS/ -- R01 GM057795/GM/NIGMS NIH HHS/ -- R01 GM057795-12/GM/NIGMS NIH HHS/ -- R01AI068718/AI/NIAID NIH HHS/ -- R01GM57795/GM/NIGMS NIH HHS/ -- T32 GM07270/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2010 Nov 18;468(7322):400-5. doi: 10.1038/nature09430. Epub 2010 Oct 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, Box 357280, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20927106" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Amino Acids/chemistry/metabolism ; Arabidopsis/chemistry/metabolism ; Arabidopsis Proteins/*chemistry/*metabolism ; Binding Sites ; Crystallography, X-Ray ; Cyclopentanes/chemistry/*metabolism ; F-Box Proteins/chemistry/metabolism ; Indenes/chemistry/metabolism ; Inositol Phosphates/*metabolism ; Isoleucine/analogs & derivatives/chemistry/metabolism ; Models, Molecular ; Molecular Sequence Data ; Oxylipins/chemistry/*metabolism ; Peptide Fragments/chemistry/metabolism ; Plant Growth Regulators/chemistry/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Repressor Proteins/*chemistry/*metabolism ; Signal Transduction
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  • 6
    Publication Date: 2010-06-26
    Description: DNA polymerase eta (Poleta) is unique among eukaryotic polymerases in its proficient ability for error-free replication through ultraviolet-induced cyclobutane pyrimidine dimers, and inactivation of Poleta (also known as POLH) in humans causes the variant form of xeroderma pigmentosum (XPV). We present the crystal structures of Saccharomyces cerevisiae Poleta (also known as RAD30) in ternary complex with a cis-syn thymine-thymine (T-T) dimer and with undamaged DNA. The structures reveal that the ability of Poleta to replicate efficiently through the ultraviolet-induced lesion derives from a simple and yet elegant mechanism, wherein the two Ts of the T-T dimer are accommodated in an active site cleft that is much more open than in other polymerases. We also show by structural, biochemical and genetic analysis that the two Ts are maintained in a stable configuration in the active site via interactions with Gln 55, Arg 73 and Met 74. Together, these features define the basis for Poleta's action on ultraviolet-damaged DNA that is crucial in suppressing the mutagenic and carcinogenic consequences of sun exposure, thereby reducing the incidence of skin cancers in humans.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030469/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3030469/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Silverstein, Timothy D -- Johnson, Robert E -- Jain, Rinku -- Prakash, Louise -- Prakash, Satya -- Aggarwal, Aneel K -- P30 EB009998/EB/NIBIB NIH HHS/ -- R01 CA107650/CA/NCI NIH HHS/ -- R01 CA107650-39/CA/NCI NIH HHS/ -- R01 ES017767/ES/NIEHS NIH HHS/ -- R01 ES017767-01/ES/NIEHS NIH HHS/ -- England -- Nature. 2010 Jun 24;465(7301):1039-43. doi: 10.1038/nature09104.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Structural and Chemical Biology, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, New York, New York 10029, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20577207" target="_blank"〉PubMed〈/a〉
    Keywords: Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; DNA Damage ; DNA-Directed DNA Polymerase/*chemistry/genetics/*metabolism ; Humans ; Kinetics ; Models, Molecular ; Mutation, Missense ; Nucleic Acid Conformation ; Protein Structure, Tertiary ; Pyrimidine Dimers/chemistry/metabolism ; Saccharomyces cerevisiae/*enzymology/genetics ; Skin Neoplasms/*enzymology/genetics ; Structure-Activity Relationship ; Xeroderma Pigmentosum/enzymology/genetics
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  • 7
    Publication Date: 2010-10-12
    Description: Blood pressure is critically controlled by angiotensins, which are vasopressor peptides specifically released by the enzyme renin from the tail of angiotensinogen-a non-inhibitory member of the serpin family of protease inhibitors. Although angiotensinogen has long been regarded as a passive substrate, the crystal structures solved here to 2.1 A resolution show that the angiotensin cleavage site is inaccessibly buried in its amino-terminal tail. The conformational rearrangement that makes this site accessible for proteolysis is revealed in our 4.4 A structure of the complex of human angiotensinogen with renin. The co-ordinated changes involved are seen to be critically linked by a conserved but labile disulphide bridge. Here we show that the reduced unbridged form of angiotensinogen is present in the circulation in a near 40:60 ratio with the oxidized sulphydryl-bridged form, which preferentially interacts with receptor-bound renin. We propose that this redox-responsive transition of angiotensinogen to a form that will more effectively release angiotensin at a cellular level contributes to the modulation of blood pressure. Specifically, we demonstrate the oxidative switch of angiotensinogen to its more active sulphydryl-bridged form in the maternal circulation in pre-eclampsia-the hypertensive crisis of pregnancy that threatens the health and survival of both mother and child.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024006/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024006/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhou, Aiwu -- Carrell, Robin W -- Murphy, Michael P -- Wei, Zhenquan -- Yan, Yahui -- Stanley, Peter L D -- Stein, Penelope E -- Broughton Pipkin, Fiona -- Read, Randy J -- 082961/Wellcome Trust/United Kingdom -- BS/05/002/18361/British Heart Foundation/United Kingdom -- MC_U105663142/Medical Research Council/United Kingdom -- PG/08/041/24818/British Heart Foundation/United Kingdom -- PG/09/072/27945/British Heart Foundation/United Kingdom -- British Heart Foundation/United Kingdom -- Medical Research Council/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2010 Nov 4;468(7320):108-11. doi: 10.1038/nature09505. Epub 2010 Oct 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK. awz20@cam.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20927107" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Angiotensinogen/blood/*chemistry/*metabolism ; Angiotensins/chemistry/*metabolism/secretion ; Blood Pressure ; Crystallography, X-Ray ; Disulfides/chemistry/metabolism ; Female ; Humans ; Kinetics ; Models, Molecular ; Molecular Sequence Data ; Oxidation-Reduction ; Oxidative Stress ; Pre-Eclampsia/blood/metabolism ; Pregnancy ; Protein Conformation ; *Protein Processing, Post-Translational ; Renin/chemistry/metabolism
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  • 8
    Publication Date: 2010-09-25
    Description: Gram-negative bacteria, such as Escherichia coli, frequently use tripartite efflux complexes in the resistance-nodulation-cell division (RND) family to expel various toxic compounds from the cell. The efflux system CusCBA is responsible for extruding biocidal Cu(I) and Ag(I) ions. No previous structural information was available for the heavy-metal efflux (HME) subfamily of the RND efflux pumps. Here we describe the crystal structures of the inner-membrane transporter CusA in the absence and presence of bound Cu(I) or Ag(I). These CusA structures provide new structural information about the HME subfamily of RND efflux pumps. The structures suggest that the metal-binding sites, formed by a three-methionine cluster, are located within the cleft region of the periplasmic domain. This cleft is closed in the apo-CusA form but open in the CusA-Cu(I) and CusA-Ag(I) structures, which directly suggests a plausible pathway for ion export. Binding of Cu(I) and Ag(I) triggers significant conformational changes in both the periplasmic and transmembrane domains. The crystal structure indicates that CusA has, in addition to the three-methionine metal-binding site, four methionine pairs-three located in the transmembrane region and one in the periplasmic domain. Genetic analysis and transport assays suggest that CusA is capable of actively picking up metal ions from the cytosol, using these methionine pairs or clusters to bind and export metal ions. These structures suggest a stepwise shuttle mechanism for transport between these sites.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946090/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946090/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Long, Feng -- Su, Chih-Chia -- Zimmermann, Michael T -- Boyken, Scott E -- Rajashankar, Kanagalaghatta R -- Jernigan, Robert L -- Yu, Edward W -- GM 072014/GM/NIGMS NIH HHS/ -- GM 074027/GM/NIGMS NIH HHS/ -- GM 081680/GM/NIGMS NIH HHS/ -- GM 086431/GM/NIGMS NIH HHS/ -- R01 GM072014/GM/NIGMS NIH HHS/ -- R01 GM074027/GM/NIGMS NIH HHS/ -- R01 GM074027-05/GM/NIGMS NIH HHS/ -- R01 GM086431/GM/NIGMS NIH HHS/ -- R01 GM086431-01A2/GM/NIGMS NIH HHS/ -- RR-15301/RR/NCRR NIH HHS/ -- England -- Nature. 2010 Sep 23;467(7314):484-8. doi: 10.1038/nature09395.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular, Cellular and Developmental Biology Interdepartmental Graduate Program, Iowa State University, Iowa 50011, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20865003" target="_blank"〉PubMed〈/a〉
    Keywords: Apoproteins/chemistry/metabolism ; Binding Sites ; Cell Membrane/metabolism ; Copper/chemistry/*metabolism ; Crystallography, X-Ray ; Cytosol/metabolism ; Escherichia coli/*chemistry ; Escherichia coli Proteins/*chemistry/*metabolism ; Ion Transport ; Membrane Transport Proteins/*chemistry/*metabolism ; Methionine/*metabolism ; Models, Biological ; Models, Molecular ; Periplasm/metabolism ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Silver/chemistry/*metabolism ; Structure-Activity Relationship
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  • 9
    Publication Date: 2010-09-30
    Description: Cell-cell signalling of semaphorin ligands through interaction with plexin receptors is important for the homeostasis and morphogenesis of many tissues and is widely studied for its role in neural connectivity, cancer, cell migration and immune responses. SEMA4D and Sema6A exemplify two diverse vertebrate, membrane-spanning semaphorin classes (4 and 6) that are capable of direct signalling through members of the two largest plexin classes, B and A, respectively. In the absence of any structural information on the plexin ectodomain or its interaction with semaphorins the extracellular specificity and mechanism controlling plexin signalling has remained unresolved. Here we present crystal structures of cognate complexes of the semaphorin-binding regions of plexins B1 and A2 with semaphorin ectodomains (human PLXNB1(1-2)-SEMA4D(ecto) and murine PlxnA2(1-4)-Sema6A(ecto)), plus unliganded structures of PlxnA2(1-4) and Sema6A(ecto). These structures, together with biophysical and cellular assays of wild-type and mutant proteins, reveal that semaphorin dimers independently bind two plexin molecules and that signalling is critically dependent on the avidity of the resulting bivalent 2:2 complex (monomeric semaphorin binds plexin but fails to trigger signalling). In combination, our data favour a cell-cell signalling mechanism involving semaphorin-stabilized plexin dimerization, possibly followed by clustering, which is consistent with previous functional data. Furthermore, the shared generic architecture of the complexes, formed through conserved contacts of the amino-terminal seven-bladed beta-propeller (sema) domains of both semaphorin and plexin, suggests that a common mode of interaction triggers all semaphorin-plexin based signalling, while distinct insertions within or between blades of the sema domains determine binding specificity.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587840/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587840/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Janssen, Bert J C -- Robinson, Ross A -- Perez-Branguli, Francesc -- Bell, Christian H -- Mitchell, Kevin J -- Siebold, Christian -- Jones, E Yvonne -- 082301/Wellcome Trust/United Kingdom -- 083111/Wellcome Trust/United Kingdom -- 10976/Cancer Research UK/United Kingdom -- A10976/Cancer Research UK/United Kingdom -- A3964/Cancer Research UK/United Kingdom -- A5261/Cancer Research UK/United Kingdom -- G0700232/Medical Research Council/United Kingdom -- G0700232(82098)/Medical Research Council/United Kingdom -- G0900084/Medical Research Council/United Kingdom -- G9900061/Medical Research Council/United Kingdom -- G9900061(69203)/Medical Research Council/United Kingdom -- Cancer Research UK/United Kingdom -- Medical Research Council/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2010 Oct 28;467(7319):1118-22. doi: 10.1038/nature09468. Epub 2010 Sep 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20877282" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antigens, CD/chemistry/genetics/metabolism ; Binding Sites ; Cell Adhesion Molecules/*chemistry/genetics/*metabolism ; Cell Communication ; Crystallography, X-Ray ; Humans ; Ligands ; Mice ; Mice, Inbred C57BL ; Models, Molecular ; NIH 3T3 Cells ; Nerve Tissue Proteins/*chemistry/genetics/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Receptors, Cell Surface/chemistry/genetics/metabolism ; Semaphorins/*chemistry/genetics/*metabolism ; *Signal Transduction ; Structure-Activity Relationship
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  • 10
    Publication Date: 2010-04-16
    Description: Tumour metastasis is the primary cause of death of cancer patients. Development of new therapeutics preventing tumour metastasis is urgently needed. Migrastatin is a natural product secreted by Streptomyces, and synthesized migrastatin analogues such as macroketone are potent inhibitors of metastatic tumour cell migration, invasion and metastasis. Here we show that these migrastatin analogues target the actin-bundling protein fascin to inhibit its activity. X-ray crystal structural studies reveal that migrastatin analogues bind to one of the actin-binding sites on fascin. Our data demonstrate that actin cytoskeletal proteins such as fascin can be explored as new molecular targets for cancer treatment, in a similar manner to the microtubule protein tubulin.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857318/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857318/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Lin -- Yang, Shengyu -- Jakoncic, Jean -- Zhang, J Jillian -- Huang, Xin-Yun -- CA136837/CA/NCI NIH HHS/ -- R01 CA136837/CA/NCI NIH HHS/ -- R01 CA136837-01A1/CA/NCI NIH HHS/ -- England -- Nature. 2010 Apr 15;464(7291):1062-6. doi: 10.1038/nature08978.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, Cornell University Weill Medical College, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20393565" target="_blank"〉PubMed〈/a〉
    Keywords: Actins/metabolism ; Animals ; Antineoplastic Agents/chemistry/metabolism/pharmacology/therapeutic use ; Binding Sites/drug effects ; Breast Neoplasms/drug therapy/pathology ; Carrier Proteins/*antagonists & inhibitors/chemistry/genetics/metabolism ; Cell Line, Tumor ; Cell Movement/drug effects ; Crystallography, X-Ray ; Drug Resistance, Neoplasm/genetics ; Female ; Humans ; Lung Neoplasms/prevention & control/secondary ; Macrolides/*chemistry/metabolism/*pharmacology/therapeutic use ; Mice ; Mice, Inbred BALB C ; Mice, Inbred NOD ; Mice, SCID ; Microfilament Proteins/*antagonists & inhibitors/chemistry/genetics/metabolism ; Models, Molecular ; Mutation/genetics ; Neoplasm Invasiveness/pathology/prevention & control ; Neoplasm Metastasis/drug therapy/pathology/*prevention & control ; Piperidones/*chemistry/metabolism/*pharmacology/therapeutic use ; Protein Conformation
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  • 11
    Publication Date: 2010-07-09
    Description: Interconversion between conductive and non-conductive forms of the K(+) channel selectivity filter underlies a variety of gating events, from flicker transitions (at the microsecond timescale) to C-type inactivation (millisecond to second timescale). Here we report the crystal structure of the Streptomyces lividans K(+) channel KcsA in its open-inactivated conformation and investigate the mechanism of C-type inactivation gating at the selectivity filter from channels 'trapped' in a series of partially open conformations. Five conformer classes were identified with openings ranging from 12 A in closed KcsA (Calpha-Calpha distances at Thr 112) to 32 A when fully open. They revealed a remarkable correlation between the degree of gate opening and the conformation and ion occupancy of the selectivity filter. We show that a gradual filter backbone reorientation leads first to a loss of the S2 ion binding site and a subsequent loss of the S3 binding site, presumably abrogating ion conduction. These structures indicate a molecular basis for C-type inactivation in K(+) channels.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033749/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033749/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cuello, Luis G -- Jogini, Vishwanath -- Cortes, D Marien -- Perozo, Eduardo -- R01 GM057846/GM/NIGMS NIH HHS/ -- R01 GM057846-15/GM/NIGMS NIH HHS/ -- R01-GM57846/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Jul 8;466(7303):203-8. doi: 10.1038/nature09153.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, University of Chicago, Illinois 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20613835" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*antagonists & inhibitors/*chemistry/metabolism ; Binding Sites ; Crystallography, X-Ray ; Electrons ; *Ion Channel Gating ; Kinetics ; Models, Biological ; Models, Molecular ; Potassium/metabolism ; Potassium Channels/*chemistry/metabolism ; Protein Conformation ; Streptomyces lividans/*chemistry ; Structure-Activity Relationship
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  • 12
    Publication Date: 2010-10-01
    Description: In most bacteria and all archaea, glutamyl-tRNA synthetase (GluRS) glutamylates both tRNA(Glu) and tRNA(Gln), and then Glu-tRNA(Gln) is selectively converted to Gln-tRNA(Gln) by a tRNA-dependent amidotransferase. The mechanisms by which the two enzymes recognize their substrate tRNA(s), and how they cooperate with each other in Gln-tRNA(Gln) synthesis, remain to be determined. Here we report the formation of the 'glutamine transamidosome' from the bacterium Thermotoga maritima, consisting of tRNA(Gln), GluRS and the heterotrimeric amidotransferase GatCAB, and its crystal structure at 3.35 A resolution. The anticodon-binding body of GluRS recognizes the common features of tRNA(Gln) and tRNA(Glu), whereas the tail body of GatCAB recognizes the outer corner of the L-shaped tRNA(Gln) in a tRNA(Gln)-specific manner. GluRS is in the productive form, as its catalytic body binds to the amino-acid-acceptor arm of tRNA(Gln). In contrast, GatCAB is in the non-productive form: the catalytic body of GatCAB contacts that of GluRS and is located near the acceptor stem of tRNA(Gln), in an appropriate site to wait for the completion of Glu-tRNA(Gln) formation by GluRS. We identified the hinges between the catalytic and anticodon-binding bodies of GluRS and between the catalytic and tail bodies of GatCAB, which allow both GluRS and GatCAB to adopt the productive and non-productive forms. The catalytic bodies of the two enzymes compete for the acceptor arm of tRNA(Gln) and therefore cannot assume their productive forms simultaneously. The transition from the present glutamylation state, with the productive GluRS and the non-productive GatCAB, to the putative amidation state, with the non-productive GluRS and the productive GatCAB, requires an intermediate state with the two enzymes in their non-productive forms, for steric reasons. The proposed mechanism explains how the transamidosome efficiently performs the two consecutive steps of Gln-tRNA(Gln) formation, with a low risk of releasing the unstable intermediate Glu-tRNA(Gln).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ito, Takuhiro -- Yokoyama, Shigeyuki -- England -- Nature. 2010 Sep 30;467(7315):612-6. doi: 10.1038/nature09411.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20882017" target="_blank"〉PubMed〈/a〉
    Keywords: Anticodon/genetics ; Biocatalysis ; Crystallography, X-Ray ; Electrophoretic Mobility Shift Assay ; Glutamate-tRNA Ligase/*chemistry/*metabolism ; Models, Molecular ; Molecular Conformation ; Nitrogenous Group Transferases/*chemistry/*metabolism ; Protein Binding ; RNA, Transfer, Gln/biosynthesis/*chemistry/*metabolism ; RNA, Transfer, Glu/chemistry/metabolism ; Staphylococcus aureus/enzymology ; Substrate Specificity ; Thermotoga maritima/*enzymology
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  • 13
    Publication Date: 2010-04-30
    Description: The interferon-inducible dynamin-like myxovirus resistance protein 1 (MxA; also called MX1) GTPase is a key mediator of cell-autonomous innate immunity against pathogens such as influenza viruses. MxA partially localizes to COPI-positive membranes of the smooth endoplasmic reticulum-Golgi intermediate compartment. At the point of infection, it redistributes to sites of viral replication and promotes missorting of essential viral constituents. It has been proposed that the middle domain and the GTPase effector domain of dynamin-like GTPases constitute a stalk that mediates oligomerization and transmits conformational changes from the G domain to the target structure; however, the molecular architecture of this stalk has remained elusive. Here we report the crystal structure of the stalk of human MxA, which folds into a four-helical bundle. This structure tightly oligomerizes in the crystal in a criss-cross pattern involving three distinct interfaces and one loop. Mutations in each of these interaction sites interfere with native assembly, oligomerization, membrane binding and antiviral activity of MxA. On the basis of these results, we propose a structural model for dynamin oligomerization and stimulated GTP hydrolysis that is consistent with previous structural predictions and has functional implications for all members of the dynamin family.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gao, Song -- von der Malsburg, Alexander -- Paeschke, Susann -- Behlke, Joachim -- Haller, Otto -- Kochs, Georg -- Daumke, Oliver -- England -- Nature. 2010 May 27;465(7297):502-6. doi: 10.1038/nature08972. Epub 2010 Apr 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Delbruck-Centrum for Molecular Medicine, Crystallography, Robert-Rossle-Strasse 10, 13125 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20428112" target="_blank"〉PubMed〈/a〉
    Keywords: Antiviral Agents/chemistry/metabolism/pharmacology ; Binding Sites ; Cell Line ; Crystallography, X-Ray ; Dynamins/*chemistry/metabolism ; GTP Phosphohydrolases/metabolism ; GTP-Binding Proteins/*chemistry/genetics/*metabolism/pharmacology ; Guanosine Triphosphate/metabolism ; Humans ; Hydrolysis ; Hydrophobic and Hydrophilic Interactions ; Influenza A Virus, H5N1 Subtype/drug effects/physiology ; Models, Molecular ; Myxovirus Resistance Proteins ; Protein Conformation ; *Protein Multimerization ; Virus Replication/drug effects
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  • 14
    Publication Date: 2010-01-22
    Description: In extremely acidic environments, enteric bacteria such as Escherichia coli rely on the amino acid antiporter AdiC to expel protons by exchanging intracellular agmatine (Agm(2+)) for extracellular arginine (Arg(+)). AdiC is a representative member of the amino acid-polyamine-organocation (APC) superfamily of membrane transporters. The structure of substrate-free AdiC revealed a homodimeric assembly, with each protomer containing 12 transmembrane segments and existing in an outward-open conformation. The overall folding of AdiC is similar to that of the Na(+)-coupled symporters. Despite these advances, it remains unclear how the substrate (arginine or agmatine) is recognized and transported by AdiC. Here we report the crystal structure of an E. coli AdiC variant bound to Arg at 3.0 A resolution. The positively charged Arg is enclosed in an acidic binding chamber, with the head groups of Arg hydrogen-bonded to main chain atoms of AdiC and the aliphatic portion of Arg stacked by hydrophobic side chains of highly conserved residues. Arg binding induces pronounced structural rearrangement in transmembrane helix 6 (TM6) and, to a lesser extent, TM2 and TM10, resulting in an occluded conformation. Structural analysis identified three potential gates, involving four aromatic residues and Glu 208, which may work in concert to differentially regulate the upload and release of Arg and Agm.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gao, Xiang -- Zhou, Lijun -- Jiao, Xuyao -- Lu, Feiran -- Yan, Chuangye -- Zeng, Xin -- Wang, Jiawei -- Shi, Yigong -- England -- Nature. 2010 Feb 11;463(7282):828-32. doi: 10.1038/nature08741. Epub 2010 Jan 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ministry of Education Protein Science Laboratory, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20090677" target="_blank"〉PubMed〈/a〉
    Keywords: Agmatine/metabolism ; Amino Acid Transport Systems/*chemistry/*metabolism ; Antiporters/*chemistry/*metabolism ; Arginine/chemistry/*metabolism ; Biological Transport ; Conserved Sequence ; Crystallography, X-Ray ; Escherichia coli Proteins/*chemistry/*metabolism ; Hydrogen Bonding ; Hydrogen-Ion Concentration ; Hydrophobic and Hydrophilic Interactions ; Protein Conformation ; Protein Folding ; Protein Multimerization ; Protons ; Static Electricity ; Structure-Activity Relationship ; Substrate Specificity
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  • 15
    Publication Date: 2010-08-20
    Description: The Na(+)/K(+)-ATPase pumps three sodium ions out of and two potassium ions into the cell for each ATP molecule that is split, thereby generating the chemical and electrical gradients across the plasma membrane that are essential in, for example, signalling, secondary transport and volume regulation in animal cells. Crystal structures of the potassium-bound form of the pump revealed an intimate docking of the alpha-subunit carboxy terminus at the transmembrane domain. Here we show that this element is a key regulator of a previously unrecognized ion pathway. Current models of P-type ATPases operate with a single ion conduit through the pump, but our data suggest an additional pathway in the Na(+)/K(+)-ATPase between the ion-binding sites and the cytoplasm. The C-terminal pathway allows a cytoplasmic proton to enter and stabilize site III when empty in the potassium-bound state, and when potassium is released the proton will also return to the cytoplasm, thus allowing an overall asymmetric stoichiometry of the transported ions. The C terminus controls the gate to the pathway. Its structure is crucial for pump function, as demonstrated by at least eight mutations in the region that cause severe neurological diseases. This novel model for ion transport by the Na(+)/K(+)-ATPase is established by electrophysiological studies of C-terminal mutations in familial hemiplegic migraine 2 (FHM2) and is further substantiated by molecular dynamics simulations. A similar ion regulation is likely to apply to the H(+)/K(+)-ATPase and the Ca(2+)-ATPase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Poulsen, Hanne -- Khandelia, Himanshu -- Morth, J Preben -- Bublitz, Maike -- Mouritsen, Ole G -- Egebjerg, Jan -- Nissen, Poul -- England -- Nature. 2010 Sep 2;467(7311):99-102. doi: 10.1038/nature09309. Epub 2010 Aug 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉PUMPKIN - Centre for Membrane Pumps in Cells and Disease, Danish National Research Foundation, Department of Molecular Biology, Aarhus University, DK-8000 Aarhus C, Denmark. hp@mb.au.dk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20720542" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Crystallography, X-Ray ; Humans ; *Ion Transport ; Migraine with Aura/genetics/*metabolism ; Models, Molecular ; Molecular Dynamics Simulation ; Oocytes/metabolism ; Potassium/metabolism ; Protons ; Sodium-Potassium-Exchanging ATPase/*chemistry/*metabolism ; Squalus acanthias/metabolism ; Sus scrofa/metabolism ; Xenopus
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  • 16
    Publication Date: 2010-02-05
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bhattacharya, Ananyo -- England -- Nature. 2010 Feb 4;463(7281):605-6. doi: 10.1038/463605a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20130626" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Child ; Crystallization ; Crystallography, X-Ray ; Diacylglycerol Kinase/chemistry ; Humans ; Magnetic Resonance Spectroscopy/*instrumentation/*methods ; Metabolomics/instrumentation/methods ; Models, Molecular ; Protein Conformation
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  • 17
    Publication Date: 2010-12-18
    Description: Recognition of modified histone species by distinct structural domains within 'reader' proteins plays a critical role in the regulation of gene expression. Readers that simultaneously recognize histones with multiple marks allow transduction of complex chromatin modification patterns into specific biological outcomes. Here we report that chromatin regulator tripartite motif-containing 24 (TRIM24) functions in humans as a reader of dual histone marks by means of tandem plant homeodomain (PHD) and bromodomain (Bromo) regions. The three-dimensional structure of the PHD-Bromo region of TRIM24 revealed a single functional unit for combinatorial recognition of unmodified H3K4 (that is, histone H3 unmodified at lysine 4, H3K4me0) and acetylated H3K23 (histone H3 acetylated at lysine 23, H3K23ac) within the same histone tail. TRIM24 binds chromatin and oestrogen receptor to activate oestrogen-dependent genes associated with cellular proliferation and tumour development. Aberrant expression of TRIM24 negatively correlates with survival of breast cancer patients. The PHD-Bromo of TRIM24 provides a structural rationale for chromatin activation through a non-canonical histone signature, establishing a new route by which chromatin readers may influence cancer pathogenesis.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058826/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058826/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tsai, Wen-Wei -- Wang, Zhanxin -- Yiu, Teresa T -- Akdemir, Kadir C -- Xia, Weiya -- Winter, Stefan -- Tsai, Cheng-Yu -- Shi, Xiaobing -- Schwarzer, Dirk -- Plunkett, William -- Aronow, Bruce -- Gozani, Or -- Fischle, Wolfgang -- Hung, Mien-Chie -- Patel, Dinshaw J -- Barton, Michelle Craig -- GM079641/GM/NIGMS NIH HHS/ -- GM081627/GM/NIGMS NIH HHS/ -- P01 GM081627/GM/NIGMS NIH HHS/ -- P01 GM081627-010003/GM/NIGMS NIH HHS/ -- P01 GM081627-020003/GM/NIGMS NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- P30DK078392-01/DK/NIDDK NIH HHS/ -- T32 HD07325/HD/NICHD NIH HHS/ -- U54 RR025216/RR/NCRR NIH HHS/ -- UL1 TR000077/TR/NCATS NIH HHS/ -- England -- Nature. 2010 Dec 16;468(7326):927-32. doi: 10.1038/nature09542.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, Program in Genes and Development, Graduate School of Biomedical Sciences, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21164480" target="_blank"〉PubMed〈/a〉
    Keywords: Acetylation ; Breast Neoplasms/*genetics/*metabolism/pathology ; Carrier Proteins/chemistry/genetics/*metabolism ; Cell Line, Tumor ; Chromatin/metabolism ; Chromatin Assembly and Disassembly ; Crystallography, X-Ray ; Estrogen Receptor alpha/metabolism ; Estrogens/metabolism ; *Gene Expression Regulation, Neoplastic/genetics ; HEK293 Cells ; Histones/chemistry/*metabolism ; Humans ; Methylation ; Protein Array Analysis ; Protein Binding ; Protein Structure, Tertiary ; Substrate Specificity ; Survival Rate
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  • 18
    Publication Date: 2010-01-08
    Description: G-protein-coupled receptors (GPCRs) are seven-transmembrane proteins that mediate most cellular responses to hormones and neurotransmitters. They are the largest group of therapeutic targets for a broad spectrum of diseases. Recent crystal structures of GPCRs have revealed structural conservation extending from the orthosteric ligand-binding site in the transmembrane core to the cytoplasmic G-protein-coupling domains. In contrast, the extracellular surface (ECS) of GPCRs is remarkably diverse and is therefore an ideal target for the discovery of subtype-selective drugs. However, little is known about the functional role of the ECS in receptor activation, or about conformational coupling of this surface to the native ligand-binding pocket. Here we use NMR spectroscopy to investigate ligand-specific conformational changes around a central structural feature in the ECS of the beta(2) adrenergic receptor: a salt bridge linking extracellular loops 2 and 3. Small-molecule drugs that bind within the transmembrane core and exhibit different efficacies towards G-protein activation (agonist, neutral antagonist and inverse agonist) also stabilize distinct conformations of the ECS. We thereby demonstrate conformational coupling between the ECS and the orthosteric binding site, showing that drugs targeting this diverse surface could function as allosteric modulators with high subtype selectivity. Moreover, these studies provide a new insight into the dynamic behaviour of GPCRs not addressable by static, inactive-state crystal structures.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805469/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805469/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bokoch, Michael P -- Zou, Yaozhong -- Rasmussen, Soren G F -- Liu, Corey W -- Nygaard, Rie -- Rosenbaum, Daniel M -- Fung, Juan Jose -- Choi, Hee-Jung -- Thian, Foon Sun -- Kobilka, Tong Sun -- Puglisi, Joseph D -- Weis, William I -- Pardo, Leonardo -- Prosser, R Scott -- Mueller, Luciano -- Kobilka, Brian K -- GM56169/GM/NIGMS NIH HHS/ -- NS028471/NS/NINDS NIH HHS/ -- R01 GM056169/GM/NIGMS NIH HHS/ -- R01 GM056169-13/GM/NIGMS NIH HHS/ -- R21 MH082313/MH/NIMH NIH HHS/ -- R21 MH082313-01A1/MH/NIMH NIH HHS/ -- R37 NS028471/NS/NINDS NIH HHS/ -- R37 NS028471-19/NS/NINDS NIH HHS/ -- England -- Nature. 2010 Jan 7;463(7277):108-12. doi: 10.1038/nature08650.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20054398" target="_blank"〉PubMed〈/a〉
    Keywords: Adrenergic beta-2 Receptor Agonists ; Adrenergic beta-2 Receptor Antagonists ; Allosteric Regulation/drug effects ; Binding Sites ; Crystallography, X-Ray ; Drug Inverse Agonism ; Ethanolamines/pharmacology ; Formoterol Fumarate ; Humans ; Ligands ; Lysine/analogs & derivatives/metabolism ; Methylation ; Models, Molecular ; Mutant Proteins ; Nuclear Magnetic Resonance, Biomolecular ; Propanolamines/metabolism/pharmacology ; Protein Structure, Tertiary/drug effects ; Receptors, Adrenergic, beta-2/*chemistry/*metabolism ; Static Electricity ; Substrate Specificity
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  • 19
    Publication Date: 2010-12-03
    Description: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3088109/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3088109/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kielian, Margaret -- R01 AI075647/AI/NIAID NIH HHS/ -- R01 AI075647-17/AI/NIAID NIH HHS/ -- R01 GM057454/GM/NIGMS NIH HHS/ -- R01 GM057454-11/GM/NIGMS NIH HHS/ -- R21 AI067931/AI/NIAID NIH HHS/ -- R21 AI067931-02/AI/NIAID NIH HHS/ -- England -- Nature. 2010 Dec 2;468(7324):645-6. doi: 10.1038/468645a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21124448" target="_blank"〉PubMed〈/a〉
    Keywords: Chikungunya virus/*chemistry/physiology ; Crystallography, X-Ray ; Membrane Fusion ; Membrane Glycoproteins/*chemistry/metabolism ; Models, Biological ; Protein Multimerization ; Protein Structure, Quaternary ; Receptors, Virus/metabolism ; Sindbis Virus/*chemistry/*physiology ; Viral Envelope Proteins/*chemistry/*metabolism ; Viral Fusion Proteins/chemistry/metabolism ; Virion/chemistry/metabolism ; *Virus Internalization
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  • 20
    Publication Date: 2010-04-20
    Description: Photosynthetic organisms adopt two different strategies for the reduction of the C17 = C18 double bond of protochlorophyllide (Pchlide) to form chlorophyllide a, the direct precursor of chlorophyll a (refs 1-4). The first involves the activity of the light-dependent Pchlide oxidoreductase, and the second involves the light-independent (dark-operative) Pchlide oxidoreductase (DPOR). DPOR is a nitrogenase-like enzyme consisting of two components, L-protein (a BchL dimer) and NB-protein (a BchN-BchB heterotetramer), which are structurally related to nitrogenase Fe protein and MoFe protein, respectively. Here we report the crystal structure of the NB-protein of DPOR from Rhodobacter capsulatus at a resolution of 2.3A. As expected, the overall structure is similar to that of nitrogenase MoFe protein: each catalytic BchN-BchB unit contains one Pchlide and one iron-sulphur cluster (NB-cluster) coordinated uniquely by one aspartate and three cysteines. Unique aspartate ligation is not necessarily needed for the cluster assembly but is essential for the catalytic activity. Specific Pchlide-binding accompanies the partial unwinding of an alpha-helix that belongs to the next catalytic BchN-BchB unit. We propose a unique trans-specific reduction mechanism in which the distorted C17-propionate of Pchlide and an aspartate from BchB serve as proton donors for C18 and C17 of Pchlide, respectively. Intriguingly, the spatial arrangement of the NB-cluster and Pchlide is almost identical to that of the P-cluster and FeMo-cofactor in nitrogenase MoFe-protein, illustrating that a common architecture exists to reduce chemically stable multibonds of porphyrin and dinitrogen.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Muraki, Norifumi -- Nomata, Jiro -- Ebata, Kozue -- Mizoguchi, Tadashi -- Shiba, Tomoo -- Tamiaki, Hitoshi -- Kurisu, Genji -- Fujita, Yuichi -- England -- Nature. 2010 May 6;465(7294):110-4. doi: 10.1038/nature08950.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Life Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20400946" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallography, X-Ray ; *Models, Molecular ; Oxidoreductases Acting on CH-CH Group Donors/*chemistry/metabolism ; Protein Structure, Tertiary ; Rhodobacter capsulatus/*enzymology
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  • 21
    Publication Date: 2010-09-24
    Description: Symplekin (Pta1 in yeast) is a scaffold in the large protein complex that is required for 3'-end cleavage and polyadenylation of eukaryotic messenger RNA precursors (pre-mRNAs); it also participates in transcription initiation and termination by RNA polymerase II (Pol II). Symplekin mediates interactions between many different proteins in this machinery, although the molecular basis for its function is not known. Here we report the crystal structure at 2.4 A resolution of the amino-terminal domain (residues 30-340) of human symplekin in a ternary complex with the Pol II carboxy-terminal domain (CTD) Ser 5 phosphatase Ssu72 (refs 7, 10-17) and a CTD Ser 5 phosphopeptide. The N-terminal domain of symplekin has the ARM or HEAT fold, with seven pairs of antiparallel alpha-helices arranged in the shape of an arc. The structure of Ssu72 has some similarity to that of low-molecular-mass phosphotyrosine protein phosphatase, although Ssu72 has a unique active-site landscape as well as extra structural features at the C terminus that are important for interaction with symplekin. Ssu72 is bound to the concave face of symplekin, and engineered mutations in this interface can abolish interactions between the two proteins. The CTD peptide is bound in the active site of Ssu72, with the pSer 5-Pro 6 peptide bond in the cis configuration, which contrasts with all other known CTD peptide conformations. Although the active site of Ssu72 is about 25 A from the interface with symplekin, we found that the symplekin N-terminal domain stimulates Ssu72 CTD phosphatase activity in vitro. Furthermore, the N-terminal domain of symplekin inhibits polyadenylation in vitro, but only when coupled to transcription. Because catalytically active Ssu72 overcomes this inhibition, our results show a role for mammalian Ssu72 in transcription-coupled pre-mRNA 3'-end processing.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038789/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038789/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xiang, Kehui -- Nagaike, Takashi -- Xiang, Song -- Kilic, Turgay -- Beh, Maia M -- Manley, James L -- Tong, Liang -- GM028983/GM/NIGMS NIH HHS/ -- GM077175/GM/NIGMS NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- R01 GM028983/GM/NIGMS NIH HHS/ -- R01 GM028983-31/GM/NIGMS NIH HHS/ -- R01 GM077175/GM/NIGMS NIH HHS/ -- R01 GM077175-04/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Oct 7;467(7316):729-33. doi: 10.1038/nature09391. Epub 2010 Sep 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Columbia University, New York, New York 10027, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20861839" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Binding Sites ; Carrier Proteins/*chemistry/genetics/*metabolism ; Catalytic Domain ; Crystallography, X-Ray ; Drosophila Proteins/chemistry ; Humans ; Models, Molecular ; Nuclear Proteins/*chemistry/genetics/*metabolism ; Phosphopeptides/chemistry/*metabolism ; Phosphoprotein Phosphatases/chemistry/genetics/metabolism ; Polyadenylation ; Protein Binding ; Protein Structure, Secondary ; Protein Structure, Tertiary ; RNA Polymerase II/*chemistry/*metabolism ; Saccharomyces cerevisiae Proteins/chemistry ; Substrate Specificity ; mRNA Cleavage and Polyadenylation Factors/chemistry
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  • 22
    Publication Date: 2010-11-03
    Description: Natural killer cells and cytotoxic T lymphocytes accomplish the critically important function of killing virus-infected and neoplastic cells. They do this by releasing the pore-forming protein perforin and granzyme proteases from cytoplasmic granules into the cleft formed between the abutting killer and target cell membranes. Perforin, a 67-kilodalton multidomain protein, oligomerizes to form pores that deliver the pro-apoptopic granzymes into the cytosol of the target cell. The importance of perforin is highlighted by the fatal consequences of congenital perforin deficiency, with more than 50 different perforin mutations linked to familial haemophagocytic lymphohistiocytosis (type 2 FHL). Here we elucidate the mechanism of perforin pore formation by determining the X-ray crystal structure of monomeric murine perforin, together with a cryo-electron microscopy reconstruction of the entire perforin pore. Perforin is a thin 'key-shaped' molecule, comprising an amino-terminal membrane attack complex perforin-like (MACPF)/cholesterol dependent cytolysin (CDC) domain followed by an epidermal growth factor (EGF) domain that, together with the extreme carboxy-terminal sequence, forms a central shelf-like structure. A C-terminal C2 domain mediates initial, Ca(2+)-dependent membrane binding. Most unexpectedly, however, electron microscopy reveals that the orientation of the perforin MACPF domain in the pore is inside-out relative to the subunit arrangement in CDCs. These data reveal remarkable flexibility in the mechanism of action of the conserved MACPF/CDC fold and provide new insights into how related immune defence molecules such as complement proteins assemble into pores.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Law, Ruby H P -- Lukoyanova, Natalya -- Voskoboinik, Ilia -- Caradoc-Davies, Tom T -- Baran, Katherine -- Dunstone, Michelle A -- D'Angelo, Michael E -- Orlova, Elena V -- Coulibaly, Fasseli -- Verschoor, Sandra -- Browne, Kylie A -- Ciccone, Annette -- Kuiper, Michael J -- Bird, Phillip I -- Trapani, Joseph A -- Saibil, Helen R -- Whisstock, James C -- 079605/Wellcome Trust/United Kingdom -- BB/D008573/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- Arthritis Research UK/United Kingdom -- Biotechnology and Biological Sciences Research Council/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2010 Nov 18;468(7322):447-51. doi: 10.1038/nature09518. Epub 2010 Oct 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, Monash University, Clayton, Melbourne, Victoria 3800, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21037563" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Membrane/*metabolism ; Cholesterol/metabolism ; Cryoelectron Microscopy ; Crystallography, X-Ray ; Epidermal Growth Factor/chemistry ; Granzymes/metabolism ; Humans ; Lymphocytes/*metabolism ; Mice ; Models, Molecular ; Pore Forming Cytotoxic Proteins/*chemistry/genetics/*metabolism/ultrastructure ; Protein Structure, Tertiary
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  • 23
    Publication Date: 2010-09-24
    Description: Transporter proteins from the MATE (multidrug and toxic compound extrusion) family are vital in metabolite transport in plants, directly affecting crop yields worldwide. MATE transporters also mediate multiple-drug resistance (MDR) in bacteria and mammals, modulating the efficacy of many pharmaceutical drugs used in the treatment of a variety of diseases. MATE transporters couple substrate transport to electrochemical gradients and are the only remaining class of MDR transporters whose structure has not been determined. Here we report the X-ray structure of the MATE transporter NorM from Vibrio cholerae determined to 3.65 A, revealing an outward-facing conformation with two portals open to the outer leaflet of the membrane and a unique topology of the predicted 12 transmembrane helices distinct from any other known MDR transporter. We also report a cation-binding site in close proximity to residues previously deemed critical for transport. This conformation probably represents a stage of the transport cycle with high affinity for monovalent cations and low affinity for substrates.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3152480/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3152480/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉He, Xiao -- Szewczyk, Paul -- Karyakin, Andrey -- Evin, Mariah -- Hong, Wen-Xu -- Zhang, Qinghai -- Chang, Geoffrey -- GM70480/GM/NIGMS NIH HHS/ -- GM73197/GM/NIGMS NIH HHS/ -- P50 GM073197/GM/NIGMS NIH HHS/ -- P50 GM073197-07/GM/NIGMS NIH HHS/ -- R01 GM070480/GM/NIGMS NIH HHS/ -- R01 GM070480-01A1/GM/NIGMS NIH HHS/ -- R01 GM070480-02/GM/NIGMS NIH HHS/ -- R01 GM070480-03/GM/NIGMS NIH HHS/ -- R01 GM070480-04/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Oct 21;467(7318):991-4. doi: 10.1038/nature09408. Epub 2010 Sep 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, CB105, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20861838" target="_blank"〉PubMed〈/a〉
    Keywords: Antiporters/*chemistry/genetics/*metabolism ; Bacterial Proteins/*chemistry/genetics/*metabolism ; Binding Sites ; Cations/chemistry/metabolism ; Crystallography, X-Ray ; Cysteine/genetics/metabolism ; Ion Transport ; Models, Molecular ; Protein Conformation ; Reproducibility of Results ; Static Electricity ; Substrate Specificity ; Vibrio cholerae/*chemistry
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  • 24
    Publication Date: 2010-10-12
    Description: DNA glycosylases that remove alkylated and deaminated purine nucleobases are essential DNA repair enzymes that protect the genome, and at the same time confound cancer alkylation therapy, by excising cytotoxic N3-methyladenine bases formed by DNA-targeting anticancer compounds. The basis for glycosylase specificity towards N3- and N7-alkylpurines is believed to result from intrinsic instability of the modified bases and not from direct enzyme functional group chemistry. Here we present crystal structures of the recently discovered Bacillus cereus AlkD glycosylase in complex with DNAs containing alkylated, mismatched and abasic nucleotides. Unlike other glycosylases, AlkD captures the extrahelical lesion in a solvent-exposed orientation, providing an illustration for how hydrolysis of N3- and N7-alkylated bases may be facilitated by increased lifetime out of the DNA helix. The structures and supporting biochemical analysis of base flipping and catalysis reveal how the HEAT repeats of AlkD distort the DNA backbone to detect non-Watson-Crick base pairs without duplex intercalation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160814/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160814/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rubinson, Emily H -- Gowda, A S Prakasha -- Spratt, Thomas E -- Gold, Barry -- Eichman, Brandt F -- P30 CA068485/CA/NCI NIH HHS/ -- P30 ES000267/ES/NIEHS NIH HHS/ -- R01 CA029088/CA/NCI NIH HHS/ -- R01 CA29088/CA/NCI NIH HHS/ -- T32 ES007028/ES/NIEHS NIH HHS/ -- England -- Nature. 2010 Nov 18;468(7322):406-11. doi: 10.1038/nature09428. Epub 2010 Oct 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20927102" target="_blank"〉PubMed〈/a〉
    Keywords: Alkylation ; Bacillus cereus/*enzymology ; Base Sequence ; Biocatalysis ; Crystallography, X-Ray ; DNA/chemistry/genetics/*metabolism ; *DNA Damage ; DNA Glycosylases/*metabolism ; DNA Repair/*physiology ; Hydrolysis ; Models, Molecular ; Nucleic Acid Conformation ; Protein Binding ; Solvents/chemistry ; Thermodynamics
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  • 25
    Publication Date: 2010-02-05
    Description: The M2 protein of influenza A virus is a membrane-spanning tetrameric proton channel targeted by the antiviral drugs amantadine and rimantadine. Resistance to these drugs has compromised their effectiveness against many influenza strains, including pandemic H1N1. A recent crystal structure of M2(22-46) showed electron densities attributed to a single amantadine in the amino-terminal half of the pore, indicating a physical occlusion mechanism for inhibition. However, a solution NMR structure of M2(18-60) showed four rimantadines bound to the carboxy-terminal lipid-facing surface of the helices, suggesting an allosteric mechanism. Here we show by solid-state NMR spectroscopy that two amantadine-binding sites exist in M2 in phospholipid bilayers. The high-affinity site, occupied by a single amantadine, is located in the N-terminal channel lumen, surrounded by residues mutated in amantadine-resistant viruses. Quantification of the protein-amantadine distances resulted in a 0.3 A-resolution structure of the high-affinity binding site. The second, low-affinity, site was observed on the C-terminal protein surface, but only when the drug reaches high concentrations in the bilayer. The orientation and dynamics of the drug are distinct in the two sites, as shown by (2)H NMR. These results indicate that amantadine physically occludes the M2 channel, thus paving the way for developing new antiviral drugs against influenza viruses. The study demonstrates the ability of solid-state NMR to elucidate small-molecule interactions with membrane proteins and determine high-resolution structures of their complexes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818718/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818718/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cady, Sarah D -- Schmidt-Rohr, Klaus -- Wang, Jun -- Soto, Cinque S -- Degrado, William F -- Hong, Mei -- AI74571/AI/NIAID NIH HHS/ -- GM088204/GM/NIGMS NIH HHS/ -- GM56423/GM/NIGMS NIH HHS/ -- R01 GM056423/GM/NIGMS NIH HHS/ -- R01 GM056423-12/GM/NIGMS NIH HHS/ -- R01 GM088204/GM/NIGMS NIH HHS/ -- R01 GM088204-01/GM/NIGMS NIH HHS/ -- U01 AI074571/AI/NIAID NIH HHS/ -- U01 AI074571-02/AI/NIAID NIH HHS/ -- England -- Nature. 2010 Feb 4;463(7281):689-92. doi: 10.1038/nature08722.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Iowa State University, Ames, Iowa 50011 2, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20130653" target="_blank"〉PubMed〈/a〉
    Keywords: Amantadine/chemistry/*metabolism/pharmacology ; Amino Acid Sequence ; Antiviral Agents/chemistry/*metabolism/pharmacology ; Binding Sites ; Crystallography, X-Ray ; Dimyristoylphosphatidylcholine/chemistry/metabolism ; Hydrogen-Ion Concentration ; Influenza A virus/*chemistry/drug effects ; Lipid Bilayers/chemistry/*metabolism ; Models, Molecular ; Molecular Sequence Data ; Nuclear Magnetic Resonance, Biomolecular ; Protein Conformation ; Structure-Activity Relationship ; Temperature ; Viral Matrix Proteins/antagonists & inhibitors/*chemistry/*metabolism
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  • 26
    Publication Date: 2010-05-28
    Description: Complex I is the first enzyme of the respiratory chain and has a central role in cellular energy production, coupling electron transfer between NADH and quinone to proton translocation by an unknown mechanism. Dysfunction of complex I has been implicated in many human neurodegenerative diseases. We have determined the structure of its hydrophilic domain previously. Here, we report the alpha-helical structure of the membrane domain of complex I from Escherichia coli at 3.9 A resolution. The antiporter-like subunits NuoL/M/N each contain 14 conserved transmembrane (TM) helices. Two of them are discontinuous, as in some transporters. Unexpectedly, subunit NuoL also contains a 110-A long amphipathic alpha-helix, spanning almost the entire length of the domain. Furthermore, we have determined the structure of the entire complex I from Thermus thermophilus at 4.5 A resolution. The L-shaped assembly consists of the alpha-helical model for the membrane domain, with 63 TM helices, and the known structure of the hydrophilic domain. The architecture of the complex provides strong clues about the coupling mechanism: the conformational changes at the interface of the two main domains may drive the long amphipathic alpha-helix of NuoL in a piston-like motion, tilting nearby discontinuous TM helices, resulting in proton translocation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Efremov, Rouslan G -- Baradaran, Rozbeh -- Sazanov, Leonid A -- MC_U105674180/Medical Research Council/United Kingdom -- Medical Research Council/United Kingdom -- England -- Nature. 2010 May 27;465(7297):441-5. doi: 10.1038/nature09066.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20505720" target="_blank"〉PubMed〈/a〉
    Keywords: Benzoquinones/metabolism ; Binding Sites ; Cell Membrane/metabolism ; Crystallography, X-Ray ; Electron Transport Complex I/*chemistry/*metabolism ; Escherichia coli/*enzymology ; Models, Molecular ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Protein Subunits/*chemistry/*metabolism ; Structure-Activity Relationship ; Thermus thermophilus/*enzymology
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  • 27
    Publication Date: 2010-04-09
    Description: Gut microbes supply the human body with energy from dietary polysaccharides through carbohydrate active enzymes, or CAZymes, which are absent in the human genome. These enzymes target polysaccharides from terrestrial plants that dominated diet throughout human evolution. The array of CAZymes in gut microbes is highly diverse, exemplified by the human gut symbiont Bacteroides thetaiotaomicron, which contains 261 glycoside hydrolases and polysaccharide lyases, as well as 208 homologues of susC and susD-genes coding for two outer membrane proteins involved in starch utilization. A fundamental question that, to our knowledge, has yet to be addressed is how this diversity evolved by acquiring new genes from microbes living outside the gut. Here we characterize the first porphyranases from a member of the marine Bacteroidetes, Zobellia galactanivorans, active on the sulphated polysaccharide porphyran from marine red algae of the genus Porphyra. Furthermore, we show that genes coding for these porphyranases, agarases and associated proteins have been transferred to the gut bacterium Bacteroides plebeius isolated from Japanese individuals. Our comparative gut metagenome analyses show that porphyranases and agarases are frequent in the Japanese population and that they are absent in metagenome data from North American individuals. Seaweeds make an important contribution to the daily diet in Japan (14.2 g per person per day), and Porphyra spp. (nori) is the most important nutritional seaweed, traditionally used to prepare sushi. This indicates that seaweeds with associated marine bacteria may have been the route by which these novel CAZymes were acquired in human gut bacteria, and that contact with non-sterile food may be a general factor in CAZyme diversity in human gut microbes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hehemann, Jan-Hendrik -- Correc, Gaelle -- Barbeyron, Tristan -- Helbert, William -- Czjzek, Mirjam -- Michel, Gurvan -- England -- Nature. 2010 Apr 8;464(7290):908-12. doi: 10.1038/nature08937.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Universite Pierre et Marie Curie, Paris, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20376150" target="_blank"〉PubMed〈/a〉
    Keywords: Adaptation, Physiological/physiology ; Bacteroides/*enzymology/genetics ; Biological Evolution ; Crystallography, X-Ray ; Cultural Diversity ; Diet ; Eukaryota/chemistry/metabolism ; Feces/enzymology/microbiology ; *Food Microbiology ; Gene Transfer, Horizontal ; Genome, Bacterial/genetics ; Glycoside Hydrolases/chemistry/isolation & purification/*metabolism ; Humans ; Intestines/*microbiology ; Japan ; *Marine Biology ; *Metagenome ; Models, Molecular ; North America ; Phylogeny ; Porphyra/chemistry/metabolism/microbiology ; Protein Conformation ; Sepharose/*analogs & derivatives/chemistry/metabolism ; Substrate Specificity
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  • 28
    Publication Date: 2010-11-12
    Description: Mononuclear iron-containing oxygenases conduct a diverse variety of oxidation functions in biology, including the oxidative demethylation of methylated nucleic acids and histones. Escherichia coli AlkB is the first such enzyme that was discovered to repair methylated nucleic acids, which are otherwise cytotoxic and/or mutagenic. AlkB human homologues are known to play pivotal roles in various processes. Here we present structural characterization of oxidation intermediates for these demethylases. Using a chemical cross-linking strategy, complexes of AlkB-double stranded DNA (dsDNA) containing 1,N(6)-etheno adenine (epsilonA), N(3)-methyl thymine (3-meT) and N(3)-methyl cytosine (3-meC) are stabilized and crystallized, respectively. Exposing these crystals, grown under anaerobic conditions containing iron(II) and alpha-ketoglutarate (alphaKG), to dioxygen initiates oxidation in crystallo. Glycol (from epsilonA) and hemiaminal (from 3-meT) intermediates are captured; a zwitterionic intermediate (from 3-meC) is also proposed, based on crystallographic observations and computational analysis. The observation of these unprecedented intermediates provides direct support for the oxidative demethylation mechanism for these demethylases. This study also depicts a general mechanistic view of how a methyl group is oxidatively removed from different biological substrates.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058853/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058853/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yi, Chengqi -- Jia, Guifang -- Hou, Guanhua -- Dai, Qing -- Zhang, Wen -- Zheng, Guanqun -- Jian, Xing -- Yang, Cai-Guang -- Cui, Qiang -- He, Chuan -- GM071440/GM/NIGMS NIH HHS/ -- GM084028/GM/NIGMS NIH HHS/ -- R01 GM071440/GM/NIGMS NIH HHS/ -- R01 GM071440-06/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Nov 11;468(7321):330-3. doi: 10.1038/nature09497.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21068844" target="_blank"〉PubMed〈/a〉
    Keywords: Catalysis ; Cross-Linking Reagents/chemistry ; Crystallization ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; *DNA Repair ; DNA Repair Enzymes/metabolism ; Dioxygenases/chemistry/*metabolism ; Escherichia coli/*enzymology ; Escherichia coli Proteins/chemistry/*metabolism ; Humans ; Iron/*metabolism ; Ketoglutaric Acids/metabolism ; Methylation ; Mixed Function Oxygenases/chemistry/*metabolism ; Models, Molecular ; Oxidation-Reduction ; Static Electricity ; Substrate Specificity
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  • 29
    facet.materialart.
    Unknown
    Nature Publishing Group (NPG)
    Publication Date: 2010-07-31
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ledford, Heidi -- England -- Nature. 2010 Jul 29;466(7306):544. doi: 10.1038/466544a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20671686" target="_blank"〉PubMed〈/a〉
    Keywords: Computational Biology ; Crystallography, X-Ray ; Drug Design ; Humans ; International Cooperation ; *Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Protein Conformation ; Protein Folding ; Receptors, G-Protein-Coupled/*chemistry/genetics/metabolism ; Species Specificity
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  • 30
    Publication Date: 2010-12-03
    Description: The multi-subunit DNA-dependent RNA polymerase (RNAP) is the principal enzyme of transcription for gene expression. Transcription is regulated by various transcription factors. Gre factor homologue 1 (Gfh1), found in the Thermus genus, is a close homologue of the well-conserved bacterial transcription factor GreA, and inhibits transcription initiation and elongation by binding directly to RNAP. The structural basis of transcription inhibition by Gfh1 has remained elusive, although the crystal structures of RNAP and Gfh1 have been determined separately. Here we report the crystal structure of Thermus thermophilus RNAP complexed with Gfh1. The amino-terminal coiled-coil domain of Gfh1 fully occludes the channel formed between the two central modules of RNAP; this channel would normally be used for nucleotide triphosphate (NTP) entry into the catalytic site. Furthermore, the tip of the coiled-coil domain occupies the NTP beta-gamma phosphate-binding site. The NTP-entry channel is expanded, because the central modules are 'ratcheted' relative to each other by approximately 7 degrees , as compared with the previously reported elongation complexes. This 'ratcheted state' is an alternative structural state, defined by a newly acquired contact between the central modules. Therefore, the shape of Gfh1 is appropriate to maintain RNAP in the ratcheted state. Simultaneously, the ratcheting expands the nucleic-acid-binding channel, and kinks the bridge helix, which connects the central modules. Taken together, the present results reveal that Gfh1 inhibits transcription by preventing NTP binding and freezing RNAP in the alternative structural state. The ratcheted state might also be associated with other aspects of transcription, such as RNAP translocation and transcription termination.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tagami, Shunsuke -- Sekine, Shun-Ichi -- Kumarevel, Thirumananseri -- Hino, Nobumasa -- Murayama, Yuko -- Kamegamori, Syunsuke -- Yamamoto, Masaki -- Sakamoto, Kensaku -- Yokoyama, Shigeyuki -- England -- Nature. 2010 Dec 16;468(7326):978-82. doi: 10.1038/nature09573. Epub 2010 Dec 1.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21124318" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/*metabolism ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; DNA-Directed RNA Polymerases/*chemistry/*metabolism ; Models, Molecular ; Protein Conformation ; Thermus thermophilus/chemistry/*enzymology ; *Transcription, Genetic
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  • 31
    Publication Date: 2010-03-20
    Description: Cobalamin (Cbl, vitamin B(12)) is a bacterial organic compound and an essential coenzyme in mammals, which take it up from the diet. This occurs by the combined action of the gastric intrinsic factor (IF) and the ileal endocytic cubam receptor formed by the 460-kilodalton (kDa) protein cubilin and the 45-kDa transmembrane protein amnionless. Loss of function of any of these proteins ultimately leads to Cbl deficiency in man. Here we present the crystal structure of the complex between IF-Cbl and the cubilin IF-Cbl-binding-region (CUB(5-8)) determined at 3.3 A resolution. The structure provides insight into how several CUB (for 'complement C1r/C1s, Uegf, Bmp1') domains collectively function as modular ligand-binding regions, and how two distant CUB domains embrace the Cbl molecule by binding the two IF domains in a Ca(2+)-dependent manner. This dual-point model provides a probable explanation of how Cbl indirectly induces ligand-receptor coupling. Finally, the comparison of Ca(2+)-binding CUB domains and the low-density lipoprotein (LDL) receptor-type A modules suggests that the electrostatic pairing of a basic ligand arginine/lysine residue with Ca(2+)-coordinating acidic aspartates/glutamates is a common theme of Ca(2+)-dependent ligand-receptor interactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Andersen, Christian Brix Folsted -- Madsen, Mette -- Storm, Tina -- Moestrup, Soren K -- Andersen, Gregers R -- England -- Nature. 2010 Mar 18;464(7287):445-8. doi: 10.1038/nature08874.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medical Biochemistry, Aarhus University, 8000 Aarhus C, Denmark.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20237569" target="_blank"〉PubMed〈/a〉
    Keywords: Aspartic Acid/metabolism ; Binding Sites ; Calcium/metabolism ; Crystallography, X-Ray ; Glutamic Acid/metabolism ; Humans ; Intrinsic Factor/*chemistry/*metabolism ; Ligands ; Models, Molecular ; Protein Binding ; Protein Structure, Tertiary ; Receptors, Cell Surface/*chemistry/*metabolism ; Static Electricity ; Vitamin B 12/*chemistry/*metabolism
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  • 32
    Publication Date: 2010-06-11
    Description: Regulation of the expression of the human immunodeficiency virus (HIV) genome is accomplished in large part by controlling transcription elongation. The viral protein Tat hijacks the host cell's RNA polymerase II elongation control machinery through interaction with the positive transcription elongation factor, P-TEFb, and directs the factor to promote productive elongation of HIV mRNA. Here we describe the crystal structure of the Tat.P-TEFb complex containing HIV-1 Tat, human Cdk9 (also known as CDK9), and human cyclin T1 (also known as CCNT1). Tat adopts a structure complementary to the surface of P-TEFb and makes extensive contacts, mainly with the cyclin T1 subunit of P-TEFb, but also with the T-loop of the Cdk9 subunit. The structure provides a plausible explanation for the tolerance of Tat to sequence variations at certain sites. Importantly, Tat induces significant conformational changes in P-TEFb. This finding lays a foundation for the design of compounds that would specifically inhibit the Tat.P-TEFb complex and block HIV replication.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885016/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885016/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tahirov, Tahir H -- Babayeva, Nigar D -- Varzavand, Katayoun -- Cooper, Jeffrey J -- Sedore, Stanley C -- Price, David H -- AI074392/AI/NIAID NIH HHS/ -- GM082923/GM/NIGMS NIH HHS/ -- GM35500/GM/NIGMS NIH HHS/ -- P30CA036727/CA/NCI NIH HHS/ -- P41 RR015301/RR/NCRR NIH HHS/ -- P41 RR015301-075443/RR/NCRR NIH HHS/ -- R01 GM035500/GM/NIGMS NIH HHS/ -- R01 GM035500-20/GM/NIGMS NIH HHS/ -- R01 GM035500-21/GM/NIGMS NIH HHS/ -- R01 GM035500-22/GM/NIGMS NIH HHS/ -- R01 GM035500-23/GM/NIGMS NIH HHS/ -- R01 GM035500-24/GM/NIGMS NIH HHS/ -- R01 GM082923/GM/NIGMS NIH HHS/ -- R01 GM082923-01A2/GM/NIGMS NIH HHS/ -- R01 GM082923-02/GM/NIGMS NIH HHS/ -- R01 GM082923-02S1/GM/NIGMS NIH HHS/ -- R21 AI074392/AI/NIAID NIH HHS/ -- R21 AI074392-01A1/AI/NIAID NIH HHS/ -- R21 AI074392-02/AI/NIAID NIH HHS/ -- R33 AI074392/AI/NIAID NIH HHS/ -- R33 AI074392-03/AI/NIAID NIH HHS/ -- RR-15301/RR/NCRR NIH HHS/ -- England -- Nature. 2010 Jun 10;465(7299):747-51. doi: 10.1038/nature09131.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-7696, USA. ttahirov@unmc.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20535204" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Animals ; Binding Sites ; Crystallography, X-Ray ; Cyclin T/chemistry/metabolism ; Cyclin-Dependent Kinase 9/chemistry/metabolism ; Enzyme Activation ; HIV-1/*chemistry ; Humans ; Models, Molecular ; Molecular Sequence Data ; Positive Transcriptional Elongation Factor B/*chemistry/*metabolism ; Protein Binding ; Protein Conformation ; tat Gene Products, Human Immunodeficiency Virus/*chemistry/genetics/*metabolism
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  • 33
    Publication Date: 2010-05-14
    Description: Nature's high-performance polymer, spider silk, consists of specific proteins, spidroins, with repetitive segments flanked by conserved non-repetitive domains. Spidroins are stored as a highly concentrated fluid dope. On silk formation, intermolecular interactions between repeat regions are established that provide strength and elasticity. How spiders manage to avoid premature spidroin aggregation before self-assembly is not yet established. A pH drop to 6.3 along the spider's spinning apparatus, altered salt composition and shear forces are believed to trigger the conversion to solid silk, but no molecular details are known. Miniature spidroins consisting of a few repetitive spidroin segments capped by the carboxy-terminal domain form metre-long silk-like fibres irrespective of pH. We discovered that incorporation of the amino-terminal domain of major ampullate spidroin 1 from the dragline of the nursery web spider Euprosthenops australis (NT) into mini-spidroins enables immediate, charge-dependent self-assembly at pH values around 6.3, but delays aggregation above pH 7. The X-ray structure of NT, determined to 1.7 A resolution, shows a homodimer of dipolar, antiparallel five-helix bundle subunits that lack homologues. The overall dimeric structure and observed charge distribution of NT is expected to be conserved through spider evolution and in all types of spidroins. Our results indicate a relay-like mechanism through which the N-terminal domain regulates spidroin assembly by inhibiting precocious aggregation during storage, and accelerating and directing self-assembly as the pH is lowered along the spider's silk extrusion duct.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Askarieh, Glareh -- Hedhammar, My -- Nordling, Kerstin -- Saenz, Alejandra -- Casals, Cristina -- Rising, Anna -- Johansson, Jan -- Knight, Stefan D -- England -- Nature. 2010 May 13;465(7295):236-8. doi: 10.1038/nature08962.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Oslo University, 1033 Blindern, 0315 Oslo, Norway.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20463740" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Circular Dichroism ; Conserved Sequence ; Crystallography, X-Ray ; Hydrogen-Ion Concentration ; Models, Molecular ; Molecular Sequence Data ; Protein Structure, Tertiary ; Sequence Alignment ; Silk/*chemistry/*metabolism/ultrastructure ; Spiders/*chemistry ; Static Electricity
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  • 34
    Publication Date: 2010-08-13
    Description: The eubacterial SOS system is a paradigm of cellular DNA damage and repair, and its activation can contribute to antibiotic resistance. Under normal conditions, LexA represses the transcription of many DNA repair proteins by binding to SOS 'boxes' in their operators. Under genotoxic stress, accumulating complexes of RecA, ATP and single-stranded DNA (ssDNA) activate LexA for autocleavage. To address how LexA recognizes its binding sites, we determined three crystal structures of Escherichia coli LexA in complex with SOS boxes. Here we report the structure of these LexA-DNA complexes. The DNA-binding domains of the LexA dimer interact with the DNA in the classical fashion of a winged helix-turn-helix motif. However, the wings of these two DNA-binding domains bind to the same minor groove of the DNA. These wing-wing contacts may explain why the spacing between the two half-sites of E. coli SOS boxes is invariant.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921665/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921665/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Adrianna P P -- Pigli, Ying Z -- Rice, Phoebe A -- GM058827/GM/NIGMS NIH HHS/ -- R01 GM058827/GM/NIGMS NIH HHS/ -- R01 GM058827-09/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Aug 12;466(7308):883-6. doi: 10.1038/nature09200.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20703307" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Bacterial Proteins/*chemistry/*metabolism ; Base Sequence ; Crystallography, X-Ray ; DNA Damage ; DNA Repair/genetics ; DNA, Bacterial/chemistry/*genetics/*metabolism ; Electrophoretic Mobility Shift Assay ; *Escherichia coli/chemistry/genetics ; Escherichia coli Proteins/chemistry/genetics/metabolism ; Models, Molecular ; Protein Binding ; *Protein Multimerization ; Protein Structure, Tertiary ; Rec A Recombinases/metabolism ; Repressor Proteins/chemistry/metabolism ; SOS Response (Genetics)/*genetics ; Serine Endopeptidases/*chemistry/*metabolism ; Winged-Helix Transcription Factors/chemistry/metabolism
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  • 35
    Publication Date: 2010-10-29
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thomine, Sebastien -- Barbier-Brygoo, Helene -- England -- Nature. 2010 Oct 28;467(7319):1058-9. doi: 10.1038/4671058a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20981091" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Arabidopsis/cytology/genetics/metabolism ; Arabidopsis Proteins/*chemistry/genetics/metabolism ; Bacterial Proteins/*chemistry/genetics/metabolism ; Crystallography, X-Ray ; Haemophilus influenzae/*chemistry/genetics ; Ion Channel Gating ; Membrane Proteins/*chemistry/genetics/metabolism ; Models, Molecular ; Phenylalanine/genetics/metabolism ; Plant Stomata/*metabolism ; Protein Folding ; *Structural Homology, Protein
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  • 36
    Publication Date: 2010-10-26
    Description: The energy-coupling factor (ECF) transporters, responsible for vitamin uptake in prokaryotes, are a unique family of membrane transporters. Each ECF transporter contains a membrane-embedded, substrate-binding protein (known as the S component), an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). The structure and transport mechanism of the ECF family remain unknown. Here we report the crystal structure of RibU, the S component of the ECF-type riboflavin transporter from Staphylococcus aureus at 3.6-A resolution. RibU contains six transmembrane segments, adopts a previously unreported transporter fold and contains a riboflavin molecule bound to the L1 loop and the periplasmic portion of transmembrane segments 4-6. Structural analysis reveals the essential ligand-binding residues, identifies the putative transport path and, with sequence alignment, uncovers conserved structural features and suggests potential mechanisms of action among the ECF transporters.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Peng -- Wang, Jiawei -- Shi, Yigong -- R01 GM084964/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Dec 2;468(7324):717-20. doi: 10.1038/nature09488. Epub 2010 Oct 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, New Jersey 08544, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20972419" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/*metabolism ; Binding Sites ; Conserved Sequence ; Crystallography, X-Ray ; Ligands ; Membrane Transport Proteins/*chemistry/classification/*metabolism ; Models, Molecular ; Movement ; Periplasm/metabolism ; Protein Folding ; Protein Structure, Tertiary ; Riboflavin/chemistry/*metabolism ; Sequence Alignment ; Staphylococcus aureus/*chemistry ; Substrate Specificity
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  • 37
    facet.materialart.
    Unknown
    Nature Publishing Group (NPG)
    Publication Date: 2010-06-11
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Baker, Monya -- England -- Nature. 2010 Jun 10;465(7299):823-6. doi: 10.1038/465823a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20535212" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Computational Biology ; Computer Simulation ; Cryoelectron Microscopy ; Crystallization ; Crystallography, X-Ray ; Drug Design ; Humans ; Lipid Bilayers/chemistry/metabolism ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Membrane Proteins/*chemistry/isolation & purification/*metabolism ; Membranes, Artificial ; *Models, Molecular ; Movement ; Protein Conformation ; Receptors, G-Protein-Coupled/chemistry/isolation & purification/metabolism ; Solubility ; Structure-Activity Relationship
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  • 38
    Publication Date: 2010-10-01
    Description: Semaphorins and their receptor plexins constitute a pleiotropic cell-signalling system that is used in a wide variety of biological processes, and both protein families have been implicated in numerous human diseases. The binding of soluble or membrane-anchored semaphorins to the membrane-distal region of the plexin ectodomain activates plexin's intrinsic GTPase-activating protein (GAP) at the cytoplasmic region, ultimately modulating cellular adhesion behaviour. However, the structural mechanism underlying the receptor activation remains largely unknown. Here we report the crystal structures of the semaphorin 6A (Sema6A) receptor-binding fragment and the plexin A2 (PlxnA2) ligand-binding fragment in both their pre-signalling (that is, before binding) and signalling (after complex formation) states. Before binding, the Sema6A ectodomain was in the expected 'face-to-face' homodimer arrangement, similar to that adopted by Sema3A and Sema4D, whereas PlxnA2 was in an unexpected 'head-on' homodimer arrangement. In contrast, the structure of the Sema6A-PlxnA2 signalling complex revealed a 2:2 heterotetramer in which the two PlxnA2 monomers dissociated from one another and docked onto the top face of the Sema6A homodimer using the same interface as the head-on homodimer, indicating that plexins undergo 'partner exchange'. Cell-based activity measurements using mutant ligands/receptors confirmed that the Sema6A face-to-face dimer arrangement is physiologically relevant and is maintained throughout signalling events. Thus, homodimer-to-heterodimer transitions of cell-surface plexin that result in a specific orientation of its molecular axis relative to the membrane may constitute the structural mechanism by which the ligand-binding 'signal' is transmitted to the cytoplasmic region, inducing GAP domain rearrangements and activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nogi, Terukazu -- Yasui, Norihisa -- Mihara, Emiko -- Matsunaga, Yukiko -- Noda, Masanori -- Yamashita, Naoya -- Toyofuku, Toshihiko -- Uchiyama, Susumu -- Goshima, Yoshio -- Kumanogoh, Atsushi -- Takagi, Junichi -- England -- Nature. 2010 Oct 28;467(7319):1123-7. doi: 10.1038/nature09473. Epub 2010 Sep 29.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20881961" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Binding Sites ; Crystallography, X-Ray ; HEK293 Cells ; Humans ; Ligands ; Mice ; Models, Molecular ; Molecular Sequence Data ; Nerve Tissue Proteins/*chemistry/genetics/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Receptors, Cell Surface/*chemistry/genetics/*metabolism ; Semaphorins/*chemistry/genetics/*metabolism ; *Signal Transduction ; Structure-Activity Relationship
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  • 39
    Publication Date: 2010-08-21
    Description: Propionyl-coenzyme A carboxylase (PCC), a mitochondrial biotin-dependent enzyme, is essential for the catabolism of the amino acids Thr, Val, Ile and Met, cholesterol and fatty acids with an odd number of carbon atoms. Deficiencies in PCC activity in humans are linked to the disease propionic acidaemia, an autosomal recessive disorder that can be fatal in infants. The holoenzyme of PCC is an alpha(6)beta(6) dodecamer, with a molecular mass of 750 kDa. The alpha-subunit contains the biotin carboxylase (BC) and biotin carboxyl carrier protein (BCCP) domains, whereas the beta-subunit supplies the carboxyltransferase (CT) activity. Here we report the crystal structure at 3.2-A resolution of a bacterial PCC alpha(6)beta(6) holoenzyme as well as cryo-electron microscopy (cryo-EM) reconstruction at 15-A resolution demonstrating a similar structure for human PCC. The structure defines the overall architecture of PCC and reveals unexpectedly that the alpha-subunits are arranged as monomers in the holoenzyme, decorating a central beta(6) hexamer. A hitherto unrecognized domain in the alpha-subunit, formed by residues between the BC and BCCP domains, is crucial for interactions with the beta-subunit. We have named it the BT domain. The structure reveals for the first time the relative positions of the BC and CT active sites in the holoenzyme. They are separated by approximately 55 A, indicating that the entire BCCP domain must translocate during catalysis. The BCCP domain is located in the active site of the beta-subunit in the current structure, providing insight for its involvement in the CT reaction. The structural information establishes a molecular basis for understanding the large collection of disease-causing mutations in PCC and is relevant for the holoenzymes of other biotin-dependent carboxylases, including 3-methylcrotonyl-CoA carboxylase (MCC) and eukaryotic acetyl-CoA carboxylase (ACC).〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2925307/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2925307/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Christine S -- Sadre-Bazzaz, Kianoush -- Shen, Yang -- Deng, Binbin -- Zhou, Z Hong -- Tong, Liang -- AI069015/AI/NIAID NIH HHS/ -- DK067238/DK/NIDDK NIH HHS/ -- GM071940/GM/NIGMS NIH HHS/ -- GM08281/GM/NIGMS NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- R01 AI069015/AI/NIAID NIH HHS/ -- R01 AI069015-04/AI/NIAID NIH HHS/ -- R01 DK067238/DK/NIDDK NIH HHS/ -- R01 DK067238-07/DK/NIDDK NIH HHS/ -- R01 GM071940/GM/NIGMS NIH HHS/ -- R01 GM071940-05/GM/NIGMS NIH HHS/ -- T32 GM008281/GM/NIGMS NIH HHS/ -- T32 GM008281-23/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Aug 19;466(7309):1001-5. doi: 10.1038/nature09302.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Columbia University, New York, New York 10027, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20725044" target="_blank"〉PubMed〈/a〉
    Keywords: Acetyl-CoA Carboxylase/chemistry/metabolism/ultrastructure ; Biocatalysis ; Biotin/metabolism ; Carbon-Nitrogen Ligases/chemistry/metabolism/ultrastructure ; Carrier Proteins/chemistry/metabolism/ultrastructure ; Catalytic Domain ; *Cryoelectron Microscopy ; Crystallography, X-Ray ; Fatty Acid Synthase, Type II ; Holoenzymes/*chemistry/genetics/metabolism/*ultrastructure ; Humans ; Methylmalonyl-CoA Decarboxylase/*chemistry/genetics/metabolism/*ultrastructure ; Models, Molecular ; Mutation/genetics ; Propionic Acidemia/enzymology/genetics ; Protein Binding ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Protein Subunits/chemistry/metabolism ; Rhodobacteraceae/enzymology ; Structure-Activity Relationship
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  • 40
    Publication Date: 2010-05-14
    Description: Neurotransmitter:Na(+) symporters (NSS) remove neurotransmitters from the synapse in a reuptake process that is driven by the Na(+) gradient. Drugs that interfere with this reuptake mechanism, such as cocaine and antidepressants, profoundly influence behaviour and mood. To probe the nature of the conformational changes that are associated with substrate binding and transport, we have developed a single-molecule fluorescence imaging assay and combined it with functional and computational studies of the prokaryotic NSS homologue LeuT. Here we show molecular details of the modulation of intracellular gating of LeuT by substrates and inhibitors, as well as by mutations that alter binding, transport or both. Our direct observations of single-molecule transitions, reflecting structural dynamics of the intracellular region of the transporter that might be masked by ensemble averaging or suppressed under crystallographic conditions, are interpreted in the context of an allosteric mechanism that couples ion and substrate binding to transport.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2940119/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2940119/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhao, Yongfang -- Terry, Daniel -- Shi, Lei -- Weinstein, Harel -- Blanchard, Scott C -- Javitch, Jonathan A -- DA022413/DA/NIDA NIH HHS/ -- DA023694/DA/NIDA NIH HHS/ -- DA12408/DA/NIDA NIH HHS/ -- DA17293/DA/NIDA NIH HHS/ -- K05 DA022413/DA/NIDA NIH HHS/ -- K99 DA023694/DA/NIDA NIH HHS/ -- K99 DA023694-02/DA/NIDA NIH HHS/ -- R01 DA017293/DA/NIDA NIH HHS/ -- England -- Nature. 2010 May 13;465(7295):188-93. doi: 10.1038/nature09057.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Molecular Recognition, Columbia University College of Physicians and Surgeons, 630 W. 168th, New York, New York 10032, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20463731" target="_blank"〉PubMed〈/a〉
    Keywords: Alanine/metabolism ; Allosteric Regulation ; Aquifoliaceae/*chemistry ; Bacterial Proteins/*chemistry/genetics/*metabolism ; Crystallography, X-Ray ; Cysteine/chemistry/metabolism ; Escherichia coli ; Fluorescence Resonance Energy Transfer ; Leucine/metabolism ; Models, Molecular ; Molecular Dynamics Simulation ; Plasma Membrane Neurotransmitter Transport ; Proteins/*chemistry/genetics/*metabolism ; Protein Conformation ; Sodium/metabolism
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  • 41
    Publication Date: 2010-04-30
    Description: Dynamin is an atypical GTPase that catalyses membrane fission during clathrin-mediated endocytosis. The mechanisms of dynamin's basal and assembly-stimulated GTP hydrolysis are unknown, though both are indirectly influenced by the GTPase effector domain (GED). Here we present the 2.0 A resolution crystal structure of a human dynamin 1-derived minimal GTPase-GED fusion protein, which was dimeric in the presence of the transition state mimic GDP.AlF(4)(-).The structure reveals dynamin's catalytic machinery and explains how assembly-stimulated GTP hydrolysis is achieved through G domain dimerization. A sodium ion present in the active site suggests that dynamin uses a cation to compensate for the developing negative charge in the transition state in the absence of an arginine finger. Structural comparison to the rat dynamin G domain reveals key conformational changes that promote G domain dimerization and stimulated hydrolysis. The structure of the GTPase-GED fusion protein dimer provides insight into the mechanisms underlying dynamin-catalysed membrane fission.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2879890/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2879890/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chappie, Joshua S -- Acharya, Sharmistha -- Leonard, Marilyn -- Schmid, Sandra L -- Dyda, Fred -- F31 MH081419/MH/NIMH NIH HHS/ -- F31 MH081419-02/MH/NIMH NIH HHS/ -- GM42455/GM/NIGMS NIH HHS/ -- MH081419/MH/NIMH NIH HHS/ -- MH61345/MH/NIMH NIH HHS/ -- R01 GM042455/GM/NIGMS NIH HHS/ -- R01 GM042455-20/GM/NIGMS NIH HHS/ -- R37 MH061345/MH/NIMH NIH HHS/ -- R37 MH061345-10/MH/NIMH NIH HHS/ -- Intramural NIH HHS/ -- England -- Nature. 2010 May 27;465(7297):435-40. doi: 10.1038/nature09032. Epub 2010 Apr 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20428113" target="_blank"〉PubMed〈/a〉
    Keywords: Aluminum Compounds/metabolism ; Amino Acid Sequence ; Biocatalysis ; Catalytic Domain/genetics ; Conserved Sequence ; Crystallography, X-Ray ; Dynamin I/*chemistry/genetics/*metabolism ; Enzyme Activation ; Fluorides/metabolism ; GTP Phosphohydrolases/*chemistry/genetics/*metabolism ; Guanosine Diphosphate/analogs & derivatives/metabolism ; Humans ; Hydrolysis ; Models, Molecular ; *Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Sodium/metabolism
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  • 42
    Publication Date: 2010-12-03
    Description: Alphaviruses are enveloped RNA viruses that have a diameter of about 700 A and can be lethal human pathogens. Entry of virus into host cells by endocytosis is controlled by two envelope glycoproteins, E1 and E2. The E2-E1 heterodimers form 80 trimeric spikes on the icosahedral virus surface, 60 with quasi-three-fold symmetry and 20 coincident with the icosahedral three-fold axes arranged with T = 4 quasi-symmetry. The E1 glycoprotein has a hydrophobic fusion loop at one end and is responsible for membrane fusion. The E2 protein is responsible for receptor binding and protects the fusion loop at neutral pH. The lower pH in the endosome induces the virions to undergo an irreversible conformational change in which E2 and E1 dissociate and E1 forms homotrimers, triggering fusion of the viral membrane with the endosomal membrane and then releasing the viral genome into the cytoplasm. Here we report the structure of an alphavirus spike, crystallized at low pH, representing an intermediate in the fusion process and clarifying the maturation process. The trimer of E2-E1 in the crystal structure is similar to the spikes in the neutral pH virus except that the E2 middle region is disordered, exposing the fusion loop. The amino- and carboxy-terminal domains of E2 each form immunoglobulin-like folds, consistent with the receptor attachment properties of E2.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057476/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057476/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Li, Long -- Jose, Joyce -- Xiang, Ye -- Kuhn, Richard J -- Rossmann, Michael G -- P01 AI055672/AI/NIAID NIH HHS/ -- P01 AI055672-07/AI/NIAID NIH HHS/ -- England -- Nature. 2010 Dec 2;468(7324):705-8. doi: 10.1038/nature09546.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, Indiana 47907-2054, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21124457" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Line ; Cryoelectron Microscopy ; Crystallography, X-Ray ; Drosophila melanogaster ; Endosomes/metabolism ; Hydrogen-Ion Concentration ; Hydrophobic and Hydrophilic Interactions ; Membrane Fusion ; Membrane Glycoproteins/chemistry/metabolism ; Models, Molecular ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Receptors, Virus/metabolism ; Sindbis Virus/*chemistry/*metabolism ; Viral Envelope Proteins/*chemistry/*metabolism ; Viral Fusion Proteins/chemistry/metabolism ; Virion/chemistry/metabolism ; *Virus Internalization
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  • 43
    Publication Date: 2010-04-07
    Description: Targeting of proteins to appropriate subcellular compartments is a crucial process in all living cells. Secretory and membrane proteins usually contain an amino-terminal signal peptide, which is recognized by the signal recognition particle (SRP) when nascent polypeptide chains emerge from the ribosome. The SRP-ribosome nascent chain complex is then targeted through its GTP-dependent interaction with SRP receptor to the protein-conducting channel on endoplasmic reticulum membrane in eukaryotes or plasma membrane in bacteria. A universally conserved component of SRP (refs 1, 2), SRP54 or its bacterial homologue, fifty-four homologue (Ffh), binds the signal peptides, which have a highly divergent sequence divisible into a positively charged n-region, an h-region commonly containing 8-20 hydrophobic residues and a polar c-region. No structure has been reported that exemplifies SRP54 binding of any signal sequence. Here we have produced a fusion protein between Sulfolobus solfataricus SRP54 (Ffh) and a signal peptide connected via a flexible linker. This fusion protein oligomerizes in solution through interaction between the SRP54 and signal peptide moieties belonging to different chains, and it is functional, as demonstrated by its ability to bind SRP RNA and SRP receptor FtsY. We present the crystal structure at 3.5 A resolution of an SRP54-signal peptide complex in the dimer, which reveals how a signal sequence is recognized by SRP54.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897128/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897128/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Janda, Claudia Y -- Li, Jade -- Oubridge, Chris -- Hernandez, Helena -- Robinson, Carol V -- Nagai, Kiyoshi -- MC_U105184330/Medical Research Council/United Kingdom -- U.1051.04.016(78933)/Medical Research Council/United Kingdom -- Medical Research Council/United Kingdom -- England -- Nature. 2010 May 27;465(7297):507-10. doi: 10.1038/nature08870. Epub 2010 Apr 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20364120" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Bacterial Proteins/metabolism ; Crystallography, X-Ray ; Mass Spectrometry ; Models, Molecular ; Molecular Sequence Data ; Protein Binding ; Protein Multimerization ; Protein Sorting Signals/*physiology ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Receptors, Cytoplasmic and Nuclear/metabolism ; Receptors, Virus/metabolism ; Recombinant Fusion Proteins/chemistry/metabolism ; Signal Recognition Particle/*chemistry/*metabolism ; Structure-Activity Relationship ; Sulfolobus solfataricus/*chemistry
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  • 44
    Publication Date: 2010-05-28
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ohnishi, Tomoko -- England -- Nature. 2010 May 27;465(7297):428-9. doi: 10.1038/465428a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20505714" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Benzoquinones/metabolism ; Crystallography, X-Ray ; Electron Transport Complex I/*chemistry/*metabolism ; Escherichia coli/*enzymology ; Humans ; Protein Structure, Secondary ; Protein Subunits/*chemistry/*metabolism ; Thermus thermophilus/*enzymology
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  • 45
    Publication Date: 2010-09-17
    Description: F-actin is a helical assembly of actin, which is a component of muscle fibres essential for contraction and has a crucial role in numerous cellular processes, such as the formation of lamellipodia and filopodia, as the most abundant component and regulator of cytoskeletons by dynamic assembly and disassembly (from G-actin to F-actin and vice versa). Actin is a ubiquitous protein and is involved in important biological functions, but the definitive high-resolution structure of F-actin remains unknown. Although a recent atomic model well reproduced X-ray fibre diffraction intensity data from a highly oriented liquid-crystalline sol specimen, its refinement without experimental phase information has certain limitations. Direct visualization of the structure by electron cryomicroscopy, however, has been difficult because it is relatively thin and flexible. Here we report the F-actin structure at 6.6 A resolution, made obtainable by recent advances in electron cryomicroscopy. The density map clearly resolves all the secondary structures of G-actin, such as alpha-helices, beta-structures and loops, and makes unambiguous modelling and refinement possible. Complex domain motions that open the nucleotide-binding pocket on F-actin formation, specific D-loop and terminal conformations, and relatively tight axial but markedly loose interprotofilament interactions hydrophilic in nature are revealed in the F-actin model, and all seem to be important for dynamic functions of actin.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fujii, Takashi -- Iwane, Atsuko H -- Yanagida, Toshio -- Namba, Keiichi -- England -- Nature. 2010 Oct 7;467(7316):724-8. doi: 10.1038/nature09372. Epub 2010 Sep 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20844487" target="_blank"〉PubMed〈/a〉
    Keywords: Actins/*chemistry/*ultrastructure ; Animals ; *Cryoelectron Microscopy ; Crystallography, X-Ray ; Hydrogen Bonding ; Models, Molecular ; Protein Structure, Secondary ; Protein Subunits ; Rabbits ; Static Electricity
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  • 46
    Publication Date: 2010-10-29
    Description: The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. Here we determine the crystal structure of a bacterial homologue (Haemophilus influenzae) of SLAC1 at 1.20 A resolution, and use structure-inspired mutagenesis to analyse the conductance properties of SLAC1 channels. SLAC1 is a symmetrical trimer composed from quasi-symmetrical subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features indicate a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics indicate that selectivity among different anions is largely a function of the energetic cost of ion dehydration.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3548404/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3548404/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Yu-Hang -- Hu, Lei -- Punta, Marco -- Bruni, Renato -- Hillerich, Brandan -- Kloss, Brian -- Rost, Burkhard -- Love, James -- Siegelbaum, Steven A -- Hendrickson, Wayne A -- R01 GM034102/GM/NIGMS NIH HHS/ -- U54 GM075026/GM/NIGMS NIH HHS/ -- U54 GM095315/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Oct 28;467(7319):1074-80. doi: 10.1038/nature09487.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20981093" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Arabidopsis/genetics/metabolism ; Arabidopsis Proteins/*chemistry ; Bacterial Proteins/*chemistry/genetics/metabolism ; Crystallography, X-Ray ; Electric Conductivity ; Haemophilus influenzae/*chemistry/genetics ; Ion Channel Gating ; Membrane Proteins/*chemistry ; Models, Molecular ; Molecular Sequence Data ; Oocytes/metabolism ; Phenylalanine/chemistry/metabolism ; Plant Stomata/*metabolism ; Static Electricity ; *Structural Homology, Protein ; Substrate Specificity ; Xenopus laevis
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  • 47
    Publication Date: 2010-08-06
    Description: Despite the success of genomics in identifying new essential bacterial genes, there is a lack of sustainable leads in antibacterial drug discovery to address increasing multidrug resistance. Type IIA topoisomerases cleave and religate DNA to regulate DNA topology and are a major class of antibacterial and anticancer drug targets, yet there is no well developed structural basis for understanding drug action. Here we report the 2.1 A crystal structure of a potent, new class, broad-spectrum antibacterial agent in complex with Staphylococcus aureus DNA gyrase and DNA, showing a new mode of inhibition that circumvents fluoroquinolone resistance in this clinically important drug target. The inhibitor 'bridges' the DNA and a transient non-catalytic pocket on the two-fold axis at the GyrA dimer interface, and is close to the active sites and fluoroquinolone binding sites. In the inhibitor complex the active site seems poised to cleave the DNA, with a single metal ion observed between the TOPRIM (topoisomerase/primase) domain and the scissile phosphate. This work provides new insights into the mechanism of topoisomerase action and a platform for structure-based drug design of a new class of antibacterial agents against a clinically proven, but conformationally flexible, enzyme class.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bax, Benjamin D -- Chan, Pan F -- Eggleston, Drake S -- Fosberry, Andrew -- Gentry, Daniel R -- Gorrec, Fabrice -- Giordano, Ilaria -- Hann, Michael M -- Hennessy, Alan -- Hibbs, Martin -- Huang, Jianzhong -- Jones, Emma -- Jones, Jo -- Brown, Kristin Koretke -- Lewis, Ceri J -- May, Earl W -- Saunders, Martin R -- Singh, Onkar -- Spitzfaden, Claus E -- Shen, Carol -- Shillings, Anthony -- Theobald, Andrew J -- Wohlkonig, Alexandre -- Pearson, Neil D -- Gwynn, Michael N -- Wellcome Trust/United Kingdom -- England -- Nature. 2010 Aug 19;466(7309):935-40. doi: 10.1038/nature09197. Epub 2010 Aug 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular Discovery Research, GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK. benjamin.d.bax@gsk.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20686482" target="_blank"〉PubMed〈/a〉
    Keywords: Anti-Bacterial Agents/*chemistry/metabolism/*pharmacology ; Apoenzymes/chemistry/metabolism ; Arginine/metabolism ; Aspartic Acid/metabolism ; Binding Sites ; Catalytic Domain ; Ciprofloxacin/chemistry/metabolism ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; DNA Cleavage ; DNA Gyrase/*chemistry/metabolism ; DNA, Superhelical/chemistry/metabolism ; Drug Design ; Drug Resistance ; Escherichia coli/enzymology ; Manganese/metabolism ; Models, Molecular ; Protein Conformation ; Quinolines/*chemistry/metabolism/*pharmacology ; Quinolones/chemistry/metabolism ; Staphylococcus aureus/*enzymology ; Structure-Activity Relationship ; *Topoisomerase II Inhibitors
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  • 48
    Publication Date: 2010-05-28
    Description: MicroRNAs (miRNAs) mediate post-transcriptional gene regulation through association with Argonaute proteins (AGOs). Crystal structures of archaeal and bacterial homologues of AGOs have shown that the MID (middle) domain mediates the interaction with the phosphorylated 5' end of the miRNA guide strand and this interaction is thought to be independent of the identity of the 5' nucleotide in these systems. However, analysis of the known sequences of eukaryotic miRNAs and co-immunoprecipitation experiments indicate that there is a clear bias for U or A at the 5' position. Here we report the crystal structure of a MID domain from a eukaryotic AGO protein, human AGO2. The structure, in complex with nucleoside monophosphates (AMP, CMP, GMP, and UMP) mimicking the 5' end of miRNAs, shows that there are specific contacts made between the base of UMP or AMP and a rigid loop in the MID domain. Notably, the structure of the loop discriminates against CMP and GMP and dissociation constants calculated from NMR titration experiments confirm these results, showing that AMP (0.26 mM) and UMP (0.12 mM) bind with up to 30-fold higher affinity than either CMP (3.6 mM) or GMP (3.3 mM). This study provides structural evidence for nucleotide-specific interactions in the MID domain of eukaryotic AGO proteins and explains the observed preference for U or A at the 5' end of miRNAs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frank, Filipp -- Sonenberg, Nahum -- Nagar, Bhushan -- MOP-82929/Canadian Institutes of Health Research/Canada -- England -- Nature. 2010 Jun 10;465(7299):818-22. doi: 10.1038/nature09039. Epub 2010 May 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, McGill University, Montreal, Quebec H3G 0B1, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20505670" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Monophosphate/metabolism ; Argonaute Proteins ; Base Sequence ; Crystallography, X-Ray ; Cytidine Monophosphate/metabolism ; Eukaryotic Initiation Factor-2/*chemistry/*metabolism ; Guanosine Monophosphate/metabolism ; Humans ; Kinetics ; Magnetic Resonance Spectroscopy ; Models, Molecular ; Protein Structure, Tertiary ; RNA, Guide/chemistry/*genetics/*metabolism ; Structure-Activity Relationship ; Substrate Specificity ; Thermodynamics ; Uridine Monophosphate/metabolism
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  • 49
    Publication Date: 2010-09-30
    Description: The major facilitator superfamily (MFS) transporters are an ancient and widespread family of secondary active transporters. In Escherichia coli, the uptake of l-fucose, a source of carbon for microorganisms, is mediated by an MFS proton symporter, FucP. Despite intensive study of the MFS transporters, atomic structure information is only available on three proteins and the outward-open conformation has yet to be captured. Here we report the crystal structure of FucP at 3.1 A resolution, which shows that it contains an outward-open, amphipathic cavity. The similarly folded amino and carboxyl domains of FucP have contrasting surface features along the transport path, with negative electrostatic potential on the N domain and hydrophobic surface on the C domain. FucP only contains two acidic residues along the transport path, Asp 46 and Glu 135, which can undergo cycles of protonation and deprotonation. Their essential role in active transport is supported by both in vivo and in vitro experiments. Structure-based biochemical analyses provide insights into energy coupling, substrate recognition and the transport mechanism of FucP.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dang, Shangyu -- Sun, Linfeng -- Huang, Yongjian -- Lu, Feiran -- Liu, Yufeng -- Gong, Haipeng -- Wang, Jiawei -- Yan, Nieng -- England -- Nature. 2010 Oct 7;467(7316):734-8. doi: 10.1038/nature09406. Epub 2010 Sep 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Bio-membrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20877283" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallography, X-Ray ; Escherichia coli/*chemistry ; Escherichia coli Proteins/*chemistry/metabolism ; Fucose/metabolism ; Hydrophobic and Hydrophilic Interactions ; Models, Biological ; Models, Molecular ; Monosaccharide Transport Proteins/*chemistry/metabolism ; Protein Conformation ; Protons ; Rotation ; Static Electricity ; Symporters/*chemistry/metabolism
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  • 50
    Publication Date: 2014-10-09
    Description: The human immunodeficiency virus type 1 (HIV-1) envelope (Env) spike, comprising three gp120 and three gp41 subunits, is a conformational machine that facilitates HIV-1 entry by rearranging from a mature unliganded state, through receptor-bound intermediates, to a post-fusion state. As the sole viral antigen on the HIV-1 virion surface, Env is both the target of neutralizing antibodies and a focus of vaccine efforts. Here we report the structure at 3.5 A resolution for an HIV-1 Env trimer captured in a mature closed state by antibodies PGT122 and 35O22. This structure reveals the pre-fusion conformation of gp41, indicates rearrangements needed for fusion activation, and defines parameters of immune evasion and immune recognition. Pre-fusion gp41 encircles amino- and carboxy-terminal strands of gp120 with four helices that form a membrane-proximal collar, fastened by insertion of a fusion peptide-proximal methionine into a gp41-tryptophan clasp. Spike rearrangements required for entry involve opening the clasp and expelling the termini. N-linked glycosylation and sequence-variable regions cover the pre-fusion closed spike; we used chronic cohorts to map the prevalence and location of effective HIV-1-neutralizing responses, which were distinguished by their recognition of N-linked glycan and tolerance for epitope-sequence variation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348022/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348022/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pancera, Marie -- Zhou, Tongqing -- Druz, Aliaksandr -- Georgiev, Ivelin S -- Soto, Cinque -- Gorman, Jason -- Huang, Jinghe -- Acharya, Priyamvada -- Chuang, Gwo-Yu -- Ofek, Gilad -- Stewart-Jones, Guillaume B E -- Stuckey, Jonathan -- Bailer, Robert T -- Joyce, M Gordon -- Louder, Mark K -- Tumba, Nancy -- Yang, Yongping -- Zhang, Baoshan -- Cohen, Myron S -- Haynes, Barton F -- Mascola, John R -- Morris, Lynn -- Munro, James B -- Blanchard, Scott C -- Mothes, Walther -- Connors, Mark -- Kwong, Peter D -- AI0678501/AI/NIAID NIH HHS/ -- AI100645/AI/NIAID NIH HHS/ -- P01 GM056550/GM/NIGMS NIH HHS/ -- P01-GM56550/GM/NIGMS NIH HHS/ -- P30 AI050410/AI/NIAID NIH HHS/ -- R01 GM098859/GM/NIGMS NIH HHS/ -- R01-GM098859/GM/NIGMS NIH HHS/ -- R21 AI100696/AI/NIAID NIH HHS/ -- R21-AI100696/AI/NIAID NIH HHS/ -- UL1 TR000142/TR/NCATS NIH HHS/ -- UM1 AI100645/AI/NIAID NIH HHS/ -- ZIA AI005023-13/Intramural NIH HHS/ -- ZIA AI005024-13/Intramural NIH HHS/ -- England -- Nature. 2014 Oct 23;514(7523):455-61. doi: 10.1038/nature13808. Epub 2014 Oct 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ; HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ; Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), Sandringham, Johannesburg 2131, South Africa. ; Departments of Medicine, Epidemiology, Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. ; Duke University Human Vaccine Institute, Departments of Medicine, Surgery, Pediatrics and Immunology, Duke University School of Medicine, and the Center for HIV/AIDS Vaccine Immunology-Immunogen Discovery at Duke University, Durham, North Carolina 27710, USA. ; 1] Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), Sandringham, Johannesburg 2131, South Africa [2] University of the Witwatersrand, Braamfontein, Johannesburg 2000, South Africa [3] Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban 4041, South Africa. ; Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, USA. ; Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25296255" target="_blank"〉PubMed〈/a〉
    Keywords: AIDS Vaccines/chemistry/immunology ; Amino Acid Sequence ; Antibodies, Neutralizing/immunology ; Cohort Studies ; Crystallography, X-Ray ; Genetic Variation ; Glycosylation ; HIV Antibodies/immunology ; HIV Envelope Protein gp120/*chemistry/genetics/*immunology ; HIV Envelope Protein gp41/*chemistry/genetics/*immunology ; HIV Infections/immunology ; Humans ; Immune Evasion ; Membrane Fusion ; Models, Molecular ; Molecular Sequence Data ; Polysaccharides/chemistry/immunology ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Subunits/chemistry/genetics/immunology ; Structural Homology, Protein ; Virus Internalization
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  • 51
    Publication Date: 2010-06-26
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Broyde, Suse -- Patel, Dinshaw J -- R01 CA028038/CA/NCI NIH HHS/ -- England -- Nature. 2010 Jun 24;465(7301):1023-4. doi: 10.1038/4651023a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20577203" target="_blank"〉PubMed〈/a〉
    Keywords: Biocatalysis ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; *DNA Damage ; *DNA Repair ; DNA-Directed DNA Polymerase/*chemistry/genetics/*metabolism ; Humans ; Models, Molecular ; Mutation, Missense/genetics ; Pyrimidine Dimers/chemistry/*metabolism ; Saccharomyces cerevisiae/*enzymology/genetics ; Skin Neoplasms/enzymology/genetics ; Structure-Activity Relationship ; Xeroderma Pigmentosum/enzymology/genetics
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  • 52
    Publication Date: 2014-02-28
    Description: The NRT1/PTR family of proton-coupled transporters are responsible for nitrogen assimilation in eukaryotes and bacteria through the uptake of peptides. However, in most plant species members of this family have evolved to transport nitrate as well as additional secondary metabolites and hormones. In response to falling nitrate levels, NRT1.1 is phosphorylated on an intracellular threonine that switches the transporter from a low-affinity to high-affinity state. Here we present both the apo and nitrate-bound crystal structures of Arabidopsis thaliana NRT1.1, which together with in vitro binding and transport data identify a key role for His 356 in nitrate binding. Our data support a model whereby phosphorylation increases structural flexibility and in turn the rate of transport. Comparison with peptide transporters further reveals how the NRT1/PTR family has evolved to recognize diverse nitrogenous ligands, while maintaining elements of a conserved coupling mechanism within this superfamily of nutrient transporters.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982047/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982047/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Parker, Joanne L -- Newstead, Simon -- G0900399/Medical Research Council/United Kingdom -- England -- Nature. 2014 Mar 6;507(7490):68-72. doi: 10.1038/nature13116. Epub 2014 Feb 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK. ; 1] Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK [2] Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0FA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24572366" target="_blank"〉PubMed〈/a〉
    Keywords: Anion Transport Proteins/*chemistry/*metabolism ; Arabidopsis/*chemistry/metabolism ; Crystallography, X-Ray ; Histidine/chemistry/metabolism ; Ion Transport ; Models, Molecular ; Nitrates/chemistry/*metabolism ; Phosphorylation ; Phosphothreonine/metabolism ; Plant Proteins/*chemistry/*metabolism ; Protein Conformation ; Protons ; Structure-Activity Relationship ; Substrate Specificity
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  • 53
    Publication Date: 2010-12-07
    Description: Membrane co-transport proteins that use a five-helix inverted repeat motif have recently emerged as one of the largest structural classes of secondary active transporters. However, despite many structural advances there is no clear evidence of how ion and substrate transport are coupled. Here we report a comprehensive study of the sodium/galactose transporter from Vibrio parahaemolyticus (vSGLT), consisting of molecular dynamics simulations, biochemical characterization and a new crystal structure of the inward-open conformation at a resolution of 2.7 A. Our data show that sodium exit causes a reorientation of transmembrane helix 1 that opens an inner gate required for substrate exit, and also triggers minor rigid-body movements in two sets of transmembrane helical bundles. This cascade of events, initiated by sodium release, ensures proper timing of ion and substrate release. Once set in motion, these molecular changes weaken substrate binding to the transporter and allow galactose readily to enter the intracellular space. Additionally, we identify an allosteric pathway between the sodium-binding sites, the unwound portion of transmembrane helix 1 and the substrate-binding site that is essential in the coupling of co-transport.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3736980/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3736980/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Watanabe, Akira -- Choe, Seungho -- Chaptal, Vincent -- Rosenberg, John M -- Wright, Ernest M -- Grabe, Michael -- Abramson, Jeff -- DK19567/DK/NIDDK NIH HHS/ -- GM078844/GM/NIGMS NIH HHS/ -- R01 DK019567/DK/NIDDK NIH HHS/ -- R01 GM078844/GM/NIGMS NIH HHS/ -- RGY0069/PHS HHS/ -- England -- Nature. 2010 Dec 16;468(7326):988-91. doi: 10.1038/nature09580. Epub 2010 Dec 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of California, Los Angeles, Los Angeles, California 90095-1759, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21131949" target="_blank"〉PubMed〈/a〉
    Keywords: Allosteric Regulation ; Binding Sites ; Biological Transport ; Crystallography, X-Ray ; Galactose/*metabolism ; Models, Molecular ; Molecular Dynamics Simulation ; Protein Conformation ; Sodium/*metabolism ; Symporters/*chemistry/*metabolism ; Vibrio parahaemolyticus/*chemistry
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  • 54
    Publication Date: 2014-12-04
    Description: Members of the dynein family, consisting of cytoplasmic and axonemal isoforms, are motors that move towards the minus ends of microtubules. Cytoplasmic dynein-1 (dynein-1) plays roles in mitosis and cellular cargo transport, and is implicated in viral infections and neurodegenerative diseases. Cytoplasmic dynein-2 (dynein-2) performs intraflagellar transport and is associated with human skeletal ciliopathies. Dyneins share a conserved motor domain that couples cycles of ATP hydrolysis with conformational changes to produce movement. Here we present the crystal structure of the human cytoplasmic dynein-2 motor bound to the ATP-hydrolysis transition state analogue ADP.vanadate. The structure reveals a closure of the motor's ring of six AAA+ domains (ATPases associated with various cellular activites: AAA1-AAA6). This induces a steric clash with the linker, the key element for the generation of movement, driving it into a conformation that is primed to produce force. Ring closure also changes the interface between the stalk and buttress coiled-coil extensions of the motor domain. This drives helix sliding in the stalk which causes the microtubule binding domain at its tip to release from the microtubule. Our structure answers the key questions of how ATP hydrolysis leads to linker remodelling and microtubule affinity regulation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336856/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336856/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schmidt, Helgo -- Zalyte, Ruta -- Urnavicius, Linas -- Carter, Andrew P -- 100387/Wellcome Trust/United Kingdom -- MC_UP_A025_1011/Medical Research Council/United Kingdom -- WT100387/Wellcome Trust/United Kingdom -- England -- Nature. 2015 Feb 19;518(7539):435-8. doi: 10.1038/nature14023. Epub 2014 Dec 1.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Francis Crick Avenue, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25470043" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Diphosphate/analogs & derivatives/metabolism ; Binding Sites ; Crystallography, X-Ray ; *Cytoplasm ; Cytoplasmic Dyneins/*chemistry/*metabolism ; Humans ; Hydrolysis ; Models, Molecular ; Movement ; Protein Conformation
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  • 55
    Publication Date: 2014-11-05
    Description: ATP-binding cassette (ABC) transporters translocate substrates across cell membranes, using energy harnessed from ATP binding and hydrolysis at their nucleotide-binding domains. ABC exporters are present both in prokaryotes and eukaryotes, with examples implicated in multidrug resistance of pathogens and cancer cells, as well as in many human diseases. TmrAB is a heterodimeric ABC exporter from the thermophilic Gram-negative eubacterium Thermus thermophilus; it is homologous to various multidrug transporters and contains one degenerate site with a non-catalytic residue next to the Walker B motif. Here we report a subnanometre-resolution structure of detergent-solubilized TmrAB in a nucleotide-free, inward-facing conformation by single-particle electron cryomicroscopy. The reconstructions clearly resolve characteristic features of ABC transporters, including helices in the transmembrane domain and nucleotide-binding domains. A cavity in the transmembrane domain is accessible laterally from the cytoplasmic side of the membrane as well as from the cytoplasm, indicating that the transporter lies in an inward-facing open conformation. The two nucleotide-binding domains remain in contact via their carboxy-terminal helices. Furthermore, comparison between our structure and the crystal structures of other ABC transporters suggests a possible trajectory of conformational changes that involves a sliding and rotating motion between the two nucleotide-binding domains during the transition from the inward-facing to outward-facing conformations.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372080/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372080/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, JungMin -- Wu, Shenping -- Tomasiak, Thomas M -- Mergel, Claudia -- Winter, Michael B -- Stiller, Sebastian B -- Robles-Colmanares, Yaneth -- Stroud, Robert M -- Tampe, Robert -- Craik, Charles S -- Cheng, Yifan -- 1P41CA196276-01/CA/NCI NIH HHS/ -- P41 CA196276/CA/NCI NIH HHS/ -- P50 GM073210/GM/NIGMS NIH HHS/ -- P50 GM082250/GM/NIGMS NIH HHS/ -- P50GM073210/GM/NIGMS NIH HHS/ -- P50GM082250/GM/NIGMS NIH HHS/ -- R01 GM024485/GM/NIGMS NIH HHS/ -- R01 GM098672/GM/NIGMS NIH HHS/ -- R01GM098672/GM/NIGMS NIH HHS/ -- R37 GM024485/GM/NIGMS NIH HHS/ -- R37GM024485/GM/NIGMS NIH HHS/ -- S10 RR026814/RR/NCRR NIH HHS/ -- S10RR026814/RR/NCRR NIH HHS/ -- England -- Nature. 2015 Jan 15;517(7534):396-400. doi: 10.1038/nature13872. Epub 2014 Nov 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, California 94158, USA. ; Department of Biochemistry and Biophysics, University of California San Francisco, 600 16th Street, San Francisco, California 94158, USA. ; Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany. ; 1] Department of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, California 94158, USA [2] Department of Biochemistry and Biophysics, University of California San Francisco, 600 16th Street, San Francisco, California 94158, USA. ; 1] Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany [2] Cluster of Excellence - Macromolecular Complexes, Goethe-University Frankfurt, Max-von-Laue-Strasse 9, D-60438 Frankfurt am Main, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25363761" target="_blank"〉PubMed〈/a〉
    Keywords: ATP-Binding Cassette Transporters/*chemistry/immunology/*ultrastructure ; Antigens/chemistry/immunology ; Binding Sites ; *Cryoelectron Microscopy ; Crystallography, X-Ray ; Models, Molecular ; Nucleotides/metabolism ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Rotation ; Thermus thermophilus/*chemistry
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  • 56
    Publication Date: 2014-10-21
    Description: Organohalide chemistry underpins many industrial and agricultural processes, and a large proportion of environmental pollutants are organohalides. Nevertheless, organohalide chemistry is not exclusively of anthropogenic origin, with natural abiotic and biological processes contributing to the global halide cycle. Reductive dehalogenases are responsible for biological dehalogenation in organohalide respiring bacteria, with substrates including polychlorinated biphenyls or dioxins. Reductive dehalogenases form a distinct subfamily of cobalamin (B12)-dependent enzymes that are usually membrane associated and oxygen sensitive, hindering detailed studies. Here we report the characterization of a soluble, oxygen-tolerant reductive dehalogenase and, by combining structure determination with EPR (electron paramagnetic resonance) spectroscopy and simulation, show that a direct interaction between the cobalamin cobalt and the substrate halogen underpins catalysis. In contrast to the carbon-cobalt bond chemistry catalysed by the other cobalamin-dependent subfamilies, we propose that reductive dehalogenases achieve reduction of the organohalide substrate via halogen-cobalt bond formation. This presents a new model in both organohalide and cobalamin (bio)chemistry that will guide future exploitation of these enzymes in bioremediation or biocatalysis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Payne, Karl A P -- Quezada, Carolina P -- Fisher, Karl -- Dunstan, Mark S -- Collins, Fraser A -- Sjuts, Hanno -- Levy, Colin -- Hay, Sam -- Rigby, Stephen E J -- Leys, David -- BB/H021523/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2015 Jan 22;517(7535):513-6. doi: 10.1038/nature13901. Epub 2014 Oct 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Manchester Institute for Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25327251" target="_blank"〉PubMed〈/a〉
    Keywords: Biocatalysis ; Cobalt/chemistry/metabolism ; Crystallography, X-Ray ; Electron Spin Resonance Spectroscopy ; *Halogenation ; Models, Molecular ; Oxidation-Reduction ; Oxidoreductases/*chemistry/*metabolism ; Oxygen/metabolism ; Phenols/chemistry/metabolism ; Phyllobacteriaceae/*enzymology ; Protein Conformation ; Solubility ; Vitamin B 12/chemistry/*metabolism
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  • 57
    Publication Date: 2014-11-11
    Description: DNA methylation is an important epigenetic modification that is essential for various developmental processes through regulating gene expression, genomic imprinting, and epigenetic inheritance. Mammalian genomic DNA methylation is established during embryogenesis by de novo DNA methyltransferases, DNMT3A and DNMT3B, and the methylation patterns vary with developmental stages and cell types. DNA methyltransferase 3-like protein (DNMT3L) is a catalytically inactive paralogue of DNMT3 enzymes, which stimulates the enzymatic activity of Dnmt3a. Recent studies have established a connection between DNA methylation and histone modifications, and revealed a histone-guided mechanism for the establishment of DNA methylation. The ATRX-DNMT3-DNMT3L (ADD) domain of Dnmt3a recognizes unmethylated histone H3 (H3K4me0). The histone H3 tail stimulates the enzymatic activity of Dnmt3a in vitro, whereas the molecular mechanism remains elusive. Here we show that DNMT3A exists in an autoinhibitory form and that the histone H3 tail stimulates its activity in a DNMT3L-independent manner. We determine the crystal structures of DNMT3A-DNMT3L (autoinhibitory form) and DNMT3A-DNMT3L-H3 (active form) complexes at 3.82 and 2.90 A resolution, respectively. Structural and biochemical analyses indicate that the ADD domain of DNMT3A interacts with and inhibits enzymatic activity of the catalytic domain (CD) through blocking its DNA-binding affinity. Histone H3 (but not H3K4me3) disrupts ADD-CD interaction, induces a large movement of the ADD domain, and thus releases the autoinhibition of DNMT3A. The finding adds another layer of regulation of DNA methylation to ensure that the enzyme is mainly activated at proper targeting loci when unmethylated H3K4 is present, and strongly supports a negative correlation between H3K4me3 and DNA methylation across the mammalian genome. Our study provides a new insight into an unexpected autoinhibition and histone H3-induced activation of the de novo DNA methyltransferase after its initial genomic positioning.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guo, Xue -- Wang, Ling -- Li, Jie -- Ding, Zhanyu -- Xiao, Jianxiong -- Yin, Xiaotong -- He, Shuang -- Shi, Pan -- Dong, Liping -- Li, Guohong -- Tian, Changlin -- Wang, Jiawei -- Cong, Yao -- Xu, Yanhui -- England -- Nature. 2015 Jan 29;517(7536):640-4. doi: 10.1038/nature13899. Epub 2014 Nov 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China [2] State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China. ; Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China. ; National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China. ; 1] High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China [2] National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei 230026, China [3] School of Life Sciences, University of Science and Technology of China, Hefei 230026, China. ; 1] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China [2] University of Chinese Academy of Science, Beijing 100049, China. ; National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China. ; State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25383530" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Catalytic Domain ; Crystallography, X-Ray ; DNA/metabolism ; DNA (Cytosine-5-)-Methyltransferase/*antagonists & ; inhibitors/*chemistry/*metabolism ; DNA Methylation ; Enzyme Activation ; Histones/*chemistry/*metabolism ; Humans ; Mice ; Models, Molecular ; Protein Structure, Tertiary ; Xenopus laevis
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  • 58
    Publication Date: 2014-11-05
    Description: Lantibiotics are a class of peptide antibiotics that contain one or more thioether bonds. The lantibiotic nisin is an antimicrobial peptide that is widely used as a food preservative to combat food-borne pathogens. Nisin contains dehydroalanine and dehydrobutyrine residues that are formed by the dehydration of Ser/Thr by the lantibiotic dehydratase NisB (ref. 2). Recent biochemical studies revealed that NisB glutamylates Ser/Thr side chains as part of the dehydration process. However, the molecular mechanism by which NisB uses glutamate to catalyse dehydration remains unresolved. Here we show that this process involves glutamyl-tRNA(Glu) to activate Ser/Thr residues. In addition, the 2.9-A crystal structure of NisB in complex with its substrate peptide NisA reveals the presence of two separate domains that catalyse the Ser/Thr glutamylation and glutamate elimination steps. The co-crystal structure also provides insights into substrate recognition by lantibiotic dehydratases. Our findings demonstrate an unexpected role for aminoacyl-tRNA in the formation of dehydroamino acids in lantibiotics, and serve as a basis for the functional characterization of the many lantibiotic-like dehydratases involved in the biosynthesis of other classes of natural products.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430201/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430201/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ortega, Manuel A -- Hao, Yue -- Zhang, Qi -- Walker, Mark C -- van der Donk, Wilfred A -- Nair, Satish K -- 5T32-GM070421/GM/NIGMS NIH HHS/ -- F32 GM112284/GM/NIGMS NIH HHS/ -- R01 GM 058822/GM/NIGMS NIH HHS/ -- R01 GM058822/GM/NIGMS NIH HHS/ -- R01 GM079038/GM/NIGMS NIH HHS/ -- S10 RR027109 A/RR/NCRR NIH HHS/ -- T32 GM070421/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Jan 22;517(7535):509-12. doi: 10.1038/nature13888. Epub 2014 Oct 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA. ; Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA. ; 1] Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA [2] Department of Chemistry and Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA. ; 1] Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA [2] Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25363770" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/classification/*metabolism ; Bacteriocins/biosynthesis/*metabolism ; Crystallography, X-Ray ; Escherichia coli/genetics ; Glutamic Acid/metabolism ; Hydro-Lyases/*chemistry/classification/*metabolism ; Lactococcus lactis/*enzymology/genetics ; Membrane Proteins/*chemistry/classification/*metabolism ; Models, Molecular ; Nisin/biosynthesis/metabolism ; Phylogeny ; Protein Structure, Tertiary ; RNA, Transfer, Glu/genetics/*metabolism ; Serine/metabolism ; Threonine/metabolism
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  • 59
    Publication Date: 2010-04-09
    Description: Recent studies have unequivocally associated the fat mass and obesity-associated (FTO) gene with the risk of obesity. In vitro FTO protein is an AlkB-like DNA/RNA demethylase with a strong preference for 3-methylthymidine (3-meT) in single-stranded DNA or 3-methyluracil (3-meU) in single-stranded RNA. Here we report the crystal structure of FTO in complex with the mononucleotide 3-meT. FTO comprises an amino-terminal AlkB-like domain and a carboxy-terminal domain with a novel fold. Biochemical assays show that these two domains interact with each other, which is required for FTO catalytic activity. In contrast with the structures of other AlkB members, FTO possesses an extra loop covering one side of the conserved jelly-roll motif. Structural comparison shows that this loop selectively competes with the unmethylated strand of the DNA duplex for binding to FTO, suggesting that it has an important role in FTO selection against double-stranded nucleic acids. The ability of FTO to distinguish 3-meT or 3-meU from other nucleotides is conferred by its hydrogen-bonding interaction with the two carbonyl oxygen atoms in 3-meT or 3-meU. Taken together, these results provide a structural basis for understanding FTO substrate-specificity, and serve as a foundation for the rational design of FTO inhibitors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Han, Zhifu -- Niu, Tianhui -- Chang, Junbiao -- Lei, Xiaoguang -- Zhao, Mingyan -- Wang, Qiang -- Cheng, Wei -- Wang, Jinjing -- Feng, Yi -- Chai, Jijie -- England -- Nature. 2010 Apr 22;464(7292):1205-9. doi: 10.1038/nature08921. Epub 2010 Apr 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Institute of Biological Sciences, No. 7 Science Park Road, Beijing 102206, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20376003" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; DNA, Single-Stranded/chemistry/metabolism ; Humans ; Methylation ; Models, Molecular ; Molecular Sequence Data ; Protein Binding ; Protein Conformation ; Proteins/*chemistry/genetics/*metabolism ; RNA/chemistry/metabolism ; Structure-Activity Relationship ; Substrate Specificity ; Thymidine/analogs & derivatives/chemistry/metabolism ; Uracil/analogs & derivatives/chemistry/metabolism
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  • 60
    Publication Date: 2011-06-15
    Description: Polyhydroxylated steroids are regulators of body shape and size in higher organisms. In metazoans, intracellular receptors recognize these molecules. Plants, however, perceive steroids at membranes, using the membrane-integral receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1). Here we report the structure of the Arabidopsis thaliana BRI1 ligand-binding domain, determined by X-ray diffraction at 2.5 A resolution. We find a superhelix of 25 twisted leucine-rich repeats (LRRs), an architecture that is strikingly different from the assembly of LRRs in animal Toll-like receptors. A 70-amino-acid island domain between LRRs 21 and 22 folds back into the interior of the superhelix to create a surface pocket for binding the plant hormone brassinolide. Known loss- and gain-of-function mutations map closely to the hormone-binding site. We propose that steroid binding to BRI1 generates a docking platform for a co-receptor that is required for receptor activation. Our findings provide insight into the activation mechanism of this highly expanded family of plant receptors that have essential roles in hormone, developmental and innate immunity signalling.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3280218/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3280218/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hothorn, Michael -- Belkhadir, Youssef -- Dreux, Marlene -- Dabi, Tsegaye -- Noel, Joseph P -- Wilson, Ian A -- Chory, Joanne -- AI042266/AI/NIAID NIH HHS/ -- R01 AI042266/AI/NIAID NIH HHS/ -- R01 AI042266-05/AI/NIAID NIH HHS/ -- R37 AI042266/AI/NIAID NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2011 Jun 12;474(7352):467-71. doi: 10.1038/nature10153.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Plant Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21666665" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Arabidopsis/*chemistry/metabolism ; Arabidopsis Proteins/*chemistry/*metabolism ; Binding Sites ; Brassinosteroids ; Cholestanols/chemistry/*metabolism ; Crystallography, X-Ray ; Enzyme Activation ; Models, Molecular ; Molecular Sequence Data ; Plant Growth Regulators/chemistry/*metabolism ; Protein Binding ; Protein Kinases/*chemistry/*metabolism ; Protein Multimerization ; Protein Structure, Tertiary ; Steroids, Heterocyclic/chemistry/*metabolism ; Structure-Activity Relationship
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  • 61
    Publication Date: 2011-04-26
    Description: The spliceosome is a dynamic macromolecular machine that assembles on pre-messenger RNA substrates and catalyses the excision of non-coding intervening sequences (introns). Four of the five major components of the spliceosome, U1, U2, U4 and U5 small nuclear ribonucleoproteins (snRNPs), contain seven Sm proteins (SmB/B', SmD1, SmD2, SmD3, SmE, SmF and SmG) in common. Following export of the U1, U2, U4 and U5 snRNAs to the cytoplasm, the seven Sm proteins, chaperoned by the survival of motor neurons (SMN) complex, assemble around a single-stranded, U-rich sequence called the Sm site in each small nuclear RNA (snRNA), to form the core domain of the respective snRNP particle. Core domain formation is a prerequisite for re-import into the nucleus, where these snRNPs mature via addition of their particle-specific proteins. Here we present a crystal structure of the U4 snRNP core domain at 3.6 A resolution, detailing how the Sm site heptad (AUUUUUG) binds inside the central hole of the heptameric ring of Sm proteins, interacting one-to-one with SmE-SmG-SmD3-SmB-SmD1-SmD2-SmF. An irregular backbone conformation of the Sm site sequence combined with the asymmetric structure of the heteromeric protein ring allows each base to interact in a distinct manner with four key residues at equivalent positions in the L3 and L5 loops of the Sm fold. A comparison of this structure with the U1 snRNP at 5.5 A resolution reveals snRNA-dependent structural changes outside the Sm fold, which may facilitate the binding of particle-specific proteins that are crucial to biogenesis of spliceosomal snRNPs.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3103711/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3103711/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Leung, Adelaine K W -- Nagai, Kiyoshi -- Li, Jade -- MC_U105184330/Medical Research Council/United Kingdom -- U.1051.04.016(78933)/Medical Research Council/United Kingdom -- Medical Research Council/United Kingdom -- England -- Nature. 2011 May 26;473(7348):536-9. doi: 10.1038/nature09956. Epub 2011 Apr 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21516107" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Crystallography, X-Ray ; Humans ; Models, Molecular ; Nucleotides/chemistry/metabolism ; Protein Folding ; Protein Structure, Tertiary ; RNA/chemistry/metabolism ; Ribonucleoprotein, U1 Small Nuclear/chemistry ; Ribonucleoprotein, U4-U6 Small Nuclear/*biosynthesis/*chemistry/metabolism ; Spliceosomes/chemistry/metabolism ; Structure-Activity Relationship
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  • 62
    Publication Date: 2010-10-22
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉van Veen, Hendrik W -- England -- Nature. 2010 Oct 21;467(7318):926-7. doi: 10.1038/467926a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20962836" target="_blank"〉PubMed〈/a〉
    Keywords: Antiporters/*chemistry/classification/*metabolism ; Bacterial Proteins/*chemistry/classification/*metabolism ; Binding Sites ; Cations/chemistry/metabolism ; Crystallography, X-Ray ; Ion Transport ; Models, Molecular ; Protein Conformation ; Substrate Specificity ; Vibrio cholerae/*chemistry
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  • 63
    Publication Date: 2010-08-27
    Description: Centromeres are specified epigenetically, and the histone H3 variant CENP-A is assembled into the chromatin of all active centromeres. Divergence from H3 raises the possibility that CENP-A generates unique chromatin features to mark physically centromere location. Here we report the crystal structure of a subnucleosomal heterotetramer, human (CENP-A-H4)(2), that reveals three distinguishing properties encoded by the residues that comprise the CENP-A targeting domain (CATD; ref. 2): (1) a CENP-A-CENP-A interface that is substantially rotated relative to the H3-H3 interface; (2) a protruding loop L1 of the opposite charge as that on H3; and (3) strong hydrophobic contacts that rigidify the CENP-A-H4 interface. Residues involved in the CENP-A-CENP-A rotation are required for efficient incorporation into centromeric chromatin, indicating specificity for an unconventional nucleosome shape. DNA topological analysis indicates that CENP-A-containing nucleosomes are octameric with conventional left-handed DNA wrapping, in contrast to other recent proposals. Our results indicate that CENP-A marks centromere location by restructuring the nucleosome from within its folded histone core.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946842/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946842/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sekulic, Nikolina -- Bassett, Emily A -- Rogers, Danielle J -- Black, Ben E -- GM08275/GM/NIGMS NIH HHS/ -- GM82989/GM/NIGMS NIH HHS/ -- R01 GM082989/GM/NIGMS NIH HHS/ -- R01 GM082989-01A1/GM/NIGMS NIH HHS/ -- R01 GM082989-02/GM/NIGMS NIH HHS/ -- R01 GM082989-03/GM/NIGMS NIH HHS/ -- T32 GM008275/GM/NIGMS NIH HHS/ -- England -- Nature. 2010 Sep 16;467(7313):347-51. doi: 10.1038/nature09323. Epub 2010 Aug 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104-6059, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20739937" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Autoantigens/*chemistry/*metabolism ; Binding Sites ; Centromere/*chemistry/*metabolism ; Chromatin Assembly and Disassembly ; Chromosomal Proteins, Non-Histone/*chemistry/*metabolism ; Crystallography, X-Ray ; DNA/chemistry/metabolism ; Deuterium Exchange Measurement ; Epistasis, Genetic ; Histones/*chemistry/*metabolism ; Humans ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions ; Models, Molecular ; Molecular Sequence Data ; Nucleosomes/chemistry/metabolism ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Rotation ; Scattering, Small Angle ; Structure-Activity Relationship ; Substrate Specificity
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  • 64
    Publication Date: 2011-10-18
    Description: Hydrogenases are abundant enzymes that catalyse the reversible interconversion of H(2) into protons and electrons at high rates. Those hydrogenases maintaining their activity in the presence of O(2) are considered to be central to H(2)-based technologies, such as enzymatic fuel cells and for light-driven H(2) production. Despite comprehensive genetic, biochemical, electrochemical and spectroscopic investigations, the molecular background allowing a structural interpretation of how the catalytic centre is protected from irreversible inactivation by O(2) has remained unclear. Here we present the crystal structure of an O(2)-tolerant [NiFe]-hydrogenase from the aerobic H(2) oxidizer Ralstonia eutropha H16 at 1.5 A resolution. The heterodimeric enzyme consists of a large subunit harbouring the catalytic centre in the H(2)-reduced state and a small subunit containing an electron relay consisting of three different iron-sulphur clusters. The cluster proximal to the active site displays an unprecedented [4Fe-3S] structure and is coordinated by six cysteines. According to the current model, this cofactor operates as an electronic switch depending on the nature of the gas molecule approaching the active site. It serves as an electron acceptor in the course of H(2) oxidation and as an electron-delivering device upon O(2) attack at the active site. This dual function is supported by the capability of the novel iron-sulphur cluster to adopt three redox states at physiological redox potentials. The second structural feature is a network of extended water cavities that may act as a channel facilitating the removal of water produced at the [NiFe] active site. These discoveries will have an impact on the design of biological and chemical H(2)-converting catalysts that are capable of cycling H(2) in air.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fritsch, Johannes -- Scheerer, Patrick -- Frielingsdorf, Stefan -- Kroschinsky, Sebastian -- Friedrich, Barbel -- Lenz, Oliver -- Spahn, Christian M T -- England -- Nature. 2011 Oct 16;479(7372):249-52. doi: 10.1038/nature10505.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Mikrobiologie, Institut fur Biologie, Humboldt-Universitat zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22002606" target="_blank"〉PubMed〈/a〉
    Keywords: Catalytic Domain ; Cell Membrane/metabolism ; Crystallography, X-Ray ; Cupriavidus necator/*enzymology ; Cysteine/metabolism ; Hydrogenase/*chemistry/metabolism ; Iron/analysis/*chemistry ; Iron-Sulfur Proteins/*chemistry/metabolism ; Models, Molecular ; Oxidation-Reduction ; Oxygen/*metabolism ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Subunits/chemistry/metabolism ; Protons ; Sulfur/analysis/*chemistry ; Water/chemistry/metabolism
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  • 65
    Publication Date: 2011-03-11
    Description: G-protein-coupled receptors (GPCRs) are seven transmembrane helix (TM) proteins that transduce signals into living cells by binding extracellular ligands and coupling to intracellular heterotrimeric G proteins (Galphabetagamma). The photoreceptor rhodopsin couples to transducin and bears its ligand 11-cis-retinal covalently bound via a protonated Schiff base to the opsin apoprotein. Absorption of a photon causes retinal cis/trans isomerization and generates the agonist all-trans-retinal in situ. After early photoproducts, the active G-protein-binding intermediate metarhodopsin II (Meta II) is formed, in which the retinal Schiff base is still intact but deprotonated. Dissociation of the proton from the Schiff base breaks a major constraint in the protein and enables further activating steps, including an outward tilt of TM6 and formation of a large cytoplasmic crevice for uptake of the interacting C terminus of the Galpha subunit. Owing to Schiff base hydrolysis, Meta II is short-lived and notoriously difficult to crystallize. We therefore soaked opsin crystals with all-trans-retinal to form Meta II, presuming that the crystal's high concentration of opsin in an active conformation (Ops*) may facilitate all-trans-retinal uptake and Schiff base formation. Here we present the 3.0 A and 2.85 A crystal structures, respectively, of Meta II alone or in complex with an 11-amino-acid C-terminal fragment derived from Galpha (GalphaCT2). GalphaCT2 binds in a large crevice at the cytoplasmic side, akin to the binding of a similar Galpha-derived peptide to Ops* (ref. 7). In the Meta II structures, the electron density from the retinal ligand seamlessly continues into the Lys 296 side chain, reflecting proper formation of the Schiff base linkage. The retinal is in a relaxed conformation and almost undistorted compared with pure crystalline all-trans-retinal. By comparison with early photoproducts we propose how retinal translocation and rotation induce the gross conformational changes characteristic for Meta II. The structures can now serve as models for the large GPCR family.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Choe, Hui-Woog -- Kim, Yong Ju -- Park, Jung Hee -- Morizumi, Takefumi -- Pai, Emil F -- Krauss, Norbert -- Hofmann, Klaus Peter -- Scheerer, Patrick -- Ernst, Oliver P -- England -- Nature. 2011 Mar 31;471(7340):651-5. doi: 10.1038/nature09789. Epub 2011 Mar 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Medizinische Physik und Biophysik - CC2, Charite - Universitatsmedizin Berlin, Chariteplatz 1, D-10117 Berlin, Germany. hwchoe@jbnu.ac.kr〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21389988" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Conserved Sequence ; Crystallization ; Crystallography, X-Ray ; GTP-Binding Protein alpha Subunits/chemistry/metabolism ; Ligands ; Models, Molecular ; Opsins/chemistry ; Peptide Fragments/chemistry/metabolism ; Protein Conformation ; Retinaldehyde/chemistry/metabolism ; Rhodopsin/*chemistry/*metabolism ; Schiff Bases/chemistry ; Static Electricity
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  • 66
    Publication Date: 2010-11-05
    Description: Channels and transporters of the ClC family cause the transmembrane movement of inorganic anions in service of a variety of biological tasks, from the unusual-the generation of the kilowatt pulses with which electric fish stun their prey-to the quotidian-the acidification of endosomes, vacuoles and lysosomes. The homodimeric architecture of ClC proteins, initially inferred from single-molecule studies of an elasmobranch Cl(-) channel and later confirmed by crystal structures of bacterial Cl(-)/H(+) antiporters, is apparently universal. Moreover, the basic machinery that enables ion movement through these proteins-the aqueous pores for anion diffusion in the channels and the ion-coupling chambers that coordinate Cl(-) and H(+) antiport in the transporters-are contained wholly within each subunit of the homodimer. The near-normal function of a bacterial ClC transporter straitjacketed by covalent crosslinks across the dimer interface and the behaviour of a concatemeric human homologue argue that the transport cycle resides within each subunit and does not require rigid-body rearrangements between subunits. However, this evidence is only inferential, and because examples are known in which quaternary rearrangements of extramembrane ClC domains that contribute to dimerization modulate transport activity, we cannot declare as definitive a 'parallel-pathways' picture in which the homodimer consists of two single-subunit transporters operating independently. A strong prediction of such a view is that it should in principle be possible to obtain a monomeric ClC. Here we exploit the known structure of a ClC Cl(-)/H(+) exchanger, ClC-ec1 from Escherichia coli, to design mutants that destabilize the dimer interface while preserving both the structure and the transport function of individual subunits. The results demonstrate that the ClC subunit alone is the basic functional unit for transport and that cross-subunit interaction is not required for Cl(-)/H(+) exchange in ClC transporters.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057488/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057488/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Robertson, Janice L -- Kolmakova-Partensky, Ludmila -- Miller, Christopher -- Howard Hughes Medical Institute/ -- England -- Nature. 2010 Dec 9;468(7325):844-7. doi: 10.1038/nature09556. Epub 2010 Nov 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21048711" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Chloride Channels/*chemistry/genetics/*metabolism ; Chlorides/metabolism ; Crystallization ; Crystallography, X-Ray ; Escherichia coli/*chemistry/genetics ; Escherichia coli Proteins/*chemistry/genetics/*metabolism ; Hydrogen/metabolism ; Liposomes/chemistry/metabolism ; Models, Molecular ; Mutant Proteins/*chemistry/genetics/*metabolism ; Phospholipids/metabolism ; Protein Conformation ; *Protein Engineering ; Protein Multimerization/genetics ; Protein Subunits/chemistry/metabolism ; Tryptophan/genetics/metabolism
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  • 67
    Publication Date: 2010-04-27
    Description: Complex enzymes containing Fe-S clusters are ubiquitous in nature, where they are involved in a number of fundamental processes including carbon dioxide fixation, nitrogen fixation and hydrogen metabolism. Hydrogen metabolism is facilitated by the activity of three evolutionarily and structurally unrelated enzymes: the [NiFe]-hydrogenases, [FeFe]-hydrogenases and [Fe]-hydrogenases (Hmd). The catalytic core of the [FeFe]-hydrogenase (HydA), termed the H-cluster, exists as a [4Fe-4S] subcluster linked by a cysteine thiolate to a modified 2Fe subcluster with unique non-protein ligands. The 2Fe subcluster and non-protein ligands are synthesized by the hydrogenase maturation enzymes HydE, HydF and HydG; however, the mechanism, synthesis and means of insertion of H-cluster components remain unclear. Here we show the structure of HydA(DeltaEFG) (HydA expressed in a genetic background devoid of the active site H-cluster biosynthetic genes hydE, hydF and hydG) revealing the presence of a [4Fe-4S] cluster and an open pocket for the 2Fe subcluster. The structure indicates that H-cluster synthesis occurs in a stepwise manner, first with synthesis and insertion of the [4Fe-4S] subcluster by generalized host-cell machinery and then with synthesis and insertion of the 2Fe subcluster by specialized hydE-, hydF- and hydG-encoded maturation machinery. Insertion of the 2Fe subcluster presumably occurs through a cationically charged channel that collapses following incorporation, as a result of conformational changes in two conserved loop regions. The structure, together with phylogenetic analysis, indicates that HydA emerged within bacteria most likely from a Nar1-like ancestor lacking the 2Fe subcluster, and that this was followed by acquisition in several unicellular eukaryotes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mulder, David W -- Boyd, Eric S -- Sarma, Ranjana -- Lange, Rachel K -- Endrizzi, James A -- Broderick, Joan B -- Peters, John W -- England -- Nature. 2010 May 13;465(7295):248-51. doi: 10.1038/nature08993. Epub 2010 Apr 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, Montana 59717, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20418861" target="_blank"〉PubMed〈/a〉
    Keywords: Catalytic Domain ; Chlamydomonas reinhardtii/*enzymology ; Clostridium/enzymology ; Crystallography, X-Ray ; Hydrogen/metabolism ; Hydrogenase/*chemistry/genetics/*metabolism ; Iron/*metabolism ; Models, Molecular ; Nitrogenase/metabolism ; Phylogeny ; Protein Conformation ; Sulfur/metabolism
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  • 68
    Publication Date: 2011-05-13
    Description: Protein translocation across the bacterial membrane, mediated by the secretory translocon SecYEG and the SecA ATPase, is enhanced by proton motive force and membrane-integrated SecDF, which associates with SecYEG. The role of SecDF has remained unclear, although it is proposed to function in later stages of translocation as well as in membrane protein biogenesis. Here, we determined the crystal structure of Thermus thermophilus SecDF at 3.3 A resolution, revealing a pseudo-symmetrical, 12-helix transmembrane domain belonging to the RND superfamily and two major periplasmic domains, P1 and P4. Higher-resolution analysis of the periplasmic domains suggested that P1, which binds an unfolded protein, undergoes functionally important conformational changes. In vitro analyses identified an ATP-independent step of protein translocation that requires both SecDF and proton motive force. Electrophysiological analyses revealed that SecDF conducts protons in a manner dependent on pH and the presence of an unfolded protein, with conserved Asp and Arg residues at the transmembrane interface between SecD and SecF playing essential roles in the movements of protons and preproteins. Therefore, we propose that SecDF functions as a membrane-integrated chaperone, powered by proton motive force, to achieve ATP-independent protein translocation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3697915/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3697915/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tsukazaki, Tomoya -- Mori, Hiroyuki -- Echizen, Yuka -- Ishitani, Ryuichiro -- Fukai, Shuya -- Tanaka, Takeshi -- Perederina, Anna -- Vassylyev, Dmitry G -- Kohno, Toshiyuki -- Maturana, Andres D -- Ito, Koreaki -- Nureki, Osamu -- R01 GM074840/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 May 11;474(7350):235-8. doi: 10.1038/nature09980.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21562494" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Arginine/metabolism ; Asparagine/metabolism ; Bacterial Proteins/*chemistry/*metabolism ; Crystallography, X-Ray ; Hydrogen-Ion Concentration ; Membrane Proteins/*chemistry/*metabolism ; Membrane Transport Proteins/*chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Periplasm/chemistry/metabolism ; Protein Structure, Tertiary ; Protein Transport ; Protein Unfolding ; Proton-Motive Force ; Static Electricity ; Structure-Activity Relationship ; Thermus thermophilus/*chemistry/cytology
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  • 69
    Publication Date: 2011-04-09
    Description: M1 protein, a major virulence factor of the leading invasive strain of group A Streptococcus, is sufficient to induce toxic-shock-like vascular leakage and tissue injury. These events are triggered by the formation of a complex between M1 and fibrinogen that, unlike M1 or fibrinogen alone, leads to neutrophil activation. Here we provide a structural explanation for the pathological properties of the complex formed between streptococcal M1 and human fibrinogen. A conformationally dynamic coiled-coil dimer of M1 was found to organize four fibrinogen molecules into a specific cross-like pattern. This pattern supported the construction of a supramolecular network that was required for neutrophil activation but was distinct from a fibrin clot. Disruption of this network into other supramolecular assemblies was not tolerated. These results have bearing on the pathophysiology of streptococcal toxic shock.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3268815/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3268815/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Macheboeuf, Pauline -- Buffalo, Cosmo -- Fu, Chi-yu -- Zinkernagel, Annelies S -- Cole, Jason N -- Johnson, John E -- Nizet, Victor -- Ghosh, Partho -- R01 AI052453/AI/NIAID NIH HHS/ -- R01 AI052453-10/AI/NIAID NIH HHS/ -- R01 AI077780/AI/NIAID NIH HHS/ -- R01 AI077780-03/AI/NIAID NIH HHS/ -- R01 GM54076/GM/NIGMS NIH HHS/ -- R21 AI071167/AI/NIAID NIH HHS/ -- T32 GM007240/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 Apr 7;472(7341):64-8. doi: 10.1038/nature09967.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21475196" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Bacterial Proteins/chemistry/*metabolism/ultrastructure ; Binding Sites ; Crystallography, X-Ray ; Fibrinogen/*chemistry/metabolism/ultrastructure ; Humans ; Models, Molecular ; Neutrophil Activation ; Protein Binding ; Protein Conformation ; Shock, Septic/microbiology/physiopathology ; Streptococcus pyogenes/chemistry/*pathogenicity ; Virulence ; Virulence Factors/chemistry/*metabolism
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  • 70
    Publication Date: 2011-03-23
    Description: The nucleobase/ascorbate transporter (NAT) proteins, also known as nucleobase/cation symporter 2 (NCS2) proteins, are responsible for the uptake of nucleobases in all kingdoms of life and for the transport of vitamin C in mammals. Despite functional characterization of the NAT family members in bacteria, fungi and mammals, detailed structural information remains unavailable. Here we report the crystal structure of a representative NAT protein, the Escherichia coli uracil/H(+) symporter UraA, in complex with uracil at a resolution of 2.8 A. UraA has a novel structural fold, with 14 transmembrane segments (TMs) divided into two inverted repeats. A pair of antiparallel beta-strands is located between TM3 and TM10 and has an important role in structural organization and substrate recognition. The structure is spatially arranged into a core domain and a gate domain. Uracil, located at the interface between the two domains, is coordinated mainly by residues from the core domain. Structural analysis suggests that alternating access of the substrate may be achieved through conformational changes of the gate domain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lu, Feiran -- Li, Shuo -- Jiang, Yang -- Jiang, Jing -- Fan, He -- Lu, Guifeng -- Deng, Dong -- Dang, Shangyu -- Zhang, Xu -- Wang, Jiawei -- Yan, Nieng -- England -- Nature. 2011 Apr 14;472(7342):243-6. doi: 10.1038/nature09885. Epub 2011 Mar 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Bio-membrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21423164" target="_blank"〉PubMed〈/a〉
    Keywords: Biological Transport ; Crystallography, X-Ray ; Escherichia coli/*chemistry ; Escherichia coli Proteins/*chemistry/*metabolism ; Hydrogen Bonding ; Membrane Transport Proteins/*chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Protein Folding ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Protons ; Structure-Activity Relationship ; Uracil/chemistry/*metabolism
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  • 71
    Publication Date: 2010-12-21
    Description: The fidelity and specificity of information flow within a cell is controlled by scaffolding proteins that assemble and link enzymes into signalling circuits. These circuits can be inhibited by bacterial effector proteins that post-translationally modify individual pathway components. However, there is emerging evidence that pathogens directly organize higher-order signalling networks through enzyme scaffolding, and the identity of the effectors and their mechanisms of action are poorly understood. Here we identify the enterohaemorrhagic Escherichia coli O157:H7 type III effector EspG as a regulator of endomembrane trafficking using a functional screen, and report ADP-ribosylation factor (ARF) GTPases and p21-activated kinases (PAKs) as its relevant host substrates. The 2.5 A crystal structure of EspG in complex with ARF6 shows how EspG blocks GTPase-activating-protein-assisted GTP hydrolysis, revealing a potent mechanism of GTPase signalling inhibition at organelle membranes. In addition, the 2.8 A crystal structure of EspG in complex with the autoinhibitory Ialpha3-helix of PAK2 defines a previously unknown catalytic site in EspG and provides an allosteric mechanism of kinase activation by a bacterial effector. Unexpectedly, ARF and PAKs are organized on adjacent surfaces of EspG, indicating its role as a 'catalytic scaffold' that effectively reprograms cellular events through the functional assembly of GTPase-kinase signalling complex.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675890/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3675890/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Selyunin, Andrey S -- Sutton, Sarah E -- Weigele, Bethany A -- Reddick, L Evan -- Orchard, Robert C -- Bresson, Stefan M -- Tomchick, Diana R -- Alto, Neal M -- 1R01AI083359-01/AI/NIAID NIH HHS/ -- 5T32AI007520-12/AI/NIAID NIH HHS/ -- R01 AI083359/AI/NIAID NIH HHS/ -- R01 AI083359-01/AI/NIAID NIH HHS/ -- T32 AI007520/AI/NIAID NIH HHS/ -- T32 AI007520-12/AI/NIAID NIH HHS/ -- England -- Nature. 2011 Jan 6;469(7328):107-11. doi: 10.1038/nature09593. Epub 2010 Dec 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21170023" target="_blank"〉PubMed〈/a〉
    Keywords: ADP-Ribosylation Factors/chemistry/*metabolism ; Allosteric Regulation ; Animals ; *Biocatalysis ; Biological Transport ; Catalytic Domain ; Cell Line ; Crystallography, X-Ray ; Endoplasmic Reticulum/metabolism ; Enzyme Activation ; Escherichia coli O157/*chemistry/metabolism ; Escherichia coli Proteins/chemistry/*metabolism ; Golgi Apparatus/metabolism ; Guanosine Triphosphate/chemistry/metabolism ; Humans ; Hydrolysis ; Intracellular Membranes/metabolism ; Mice ; Models, Molecular ; Protein Binding ; Protein Conformation ; Protein Interaction Mapping ; Protein Unfolding ; Rats ; *Signal Transduction ; Two-Hybrid System Techniques ; p21-Activated Kinases/chemistry/*metabolism
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  • 72
    Publication Date: 2011-01-21
    Description: The mature capsids of human immunodeficiency virus type 1 (HIV-1) and other retroviruses are fullerene shells, composed of the viral CA protein, that enclose the viral genome and facilitate its delivery into new host cells. Retroviral CA proteins contain independently folded amino (N)- and carboxy (C)-terminal domains (NTD and CTD) that are connected by a flexible linker. The NTD forms either hexameric or pentameric rings, whereas the CTD forms symmetric homodimers that connect the rings into a hexagonal lattice. We previously used a disulphide crosslinking strategy to enable isolation and crystallization of soluble HIV-1 CA hexamers. Here we use the same approach to solve the X-ray structure of the HIV-1 CA pentamer at 2.5 A resolution. Two mutant CA proteins with engineered disulphides at different positions (P17C/T19C and N21C/A22C) converged onto the same quaternary structure, indicating that the disulphide-crosslinked proteins recapitulate the structure of the native pentamer. Assembly of the quasi-equivalent hexamers and pentamers requires remarkably subtle rearrangements in subunit interactions, and appears to be controlled by an electrostatic switch that favours hexamers over pentamers. This study completes the gallery of substructures describing the components of the HIV-1 capsid and enables atomic-level modelling of the complete capsid. Rigid-body rotations around two assembly interfaces appear sufficient to generate the full range of continuously varying lattice curvature in the fullerene cone.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075868/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075868/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pornillos, Owen -- Ganser-Pornillos, Barbie K -- Yeager, Mark -- P50 GM082545/GM/NIGMS NIH HHS/ -- P50 GM082545-05/GM/NIGMS NIH HHS/ -- P50-GM082545/GM/NIGMS NIH HHS/ -- R01 GM066087/GM/NIGMS NIH HHS/ -- R01 GM066087-09/GM/NIGMS NIH HHS/ -- R01-GM066087/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 Jan 20;469(7330):424-7. doi: 10.1038/nature09640.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21248851" target="_blank"〉PubMed〈/a〉
    Keywords: Capsid Proteins/*chemistry ; Crystallization ; Crystallography, X-Ray ; Disulfides/chemistry ; Fullerenes/chemistry ; HIV-1/*chemistry ; Models, Molecular ; Protein Binding ; Protein Multimerization ; Protein Structure, Quaternary ; Rotation ; Static Electricity
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  • 73
    Publication Date: 2011-06-17
    Description: Transforming growth factor (TGF)-beta is stored in the extracellular matrix as a latent complex with its prodomain. Activation of TGF-beta1 requires the binding of alpha(v) integrin to an RGD sequence in the prodomain and exertion of force on this domain, which is held in the extracellular matrix by latent TGF-beta binding proteins. Crystals of dimeric porcine proTGF-beta1 reveal a ring-shaped complex, a novel fold for the prodomain, and show how the prodomain shields the growth factor from recognition by receptors and alters its conformation. Complex formation between alpha(v)beta(6) integrin and the prodomain is insufficient for TGF-beta1 release. Force-dependent activation requires unfastening of a 'straitjacket' that encircles each growth-factor monomer at a position that can be locked by a disulphide bond. Sequences of all 33 TGF-beta family members indicate a similar prodomain fold. The structure provides insights into the regulation of a family of growth and differentiation factors of fundamental importance in morphogenesis and homeostasis.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717672/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717672/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shi, Minlong -- Zhu, Jianghai -- Wang, Rui -- Chen, Xing -- Mi, Lizhi -- Walz, Thomas -- Springer, Timothy A -- P01 HL103526/HL/NHLBI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2011 Jun 15;474(7351):343-9. doi: 10.1038/nature10152.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Immune Disease Institute, Children's Hospital Boston and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21677751" target="_blank"〉PubMed〈/a〉
    Keywords: Activins/metabolism ; Amino Acid Motifs ; Amino Acid Sequence ; Animals ; Antigens, Neoplasm/chemistry/metabolism ; Camurati-Engelmann Syndrome/genetics ; Cell Line ; Crystallography, X-Ray ; HEK293 Cells ; Humans ; Integrins/chemistry/metabolism ; Latent TGF-beta Binding Proteins/chemistry/metabolism ; Models, Molecular ; Molecular Sequence Data ; Multigene Family ; Mutation/genetics ; Oligopeptides/chemistry/metabolism ; Protein Structure, Tertiary ; Receptors, Transforming Growth Factor beta/chemistry/metabolism ; Swine ; Transforming Growth Factor beta1/biosynthesis/*chemistry/genetics/*metabolism
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  • 74
    Publication Date: 2011-03-04
    Description: Regulated proteolysis by ATP-dependent proteases is universal in all living cells. Bacterial ClpC, a member of the Clp/Hsp100 family of AAA+ proteins (ATPases associated with diverse cellular activities) with two nucleotide-binding domains (D1 and D2), requires the adaptor protein MecA for activation and substrate targeting. The activated, hexameric MecA-ClpC molecular machine harnesses the energy of ATP binding and hydrolysis to unfold specific substrate proteins and translocate the unfolded polypeptide to the ClpP protease for degradation. Here we report three related crystal structures: a heterodimer between MecA and the amino domain of ClpC, a heterododecamer between MecA and D2-deleted ClpC, and a hexameric complex between MecA and full-length ClpC. In conjunction with biochemical analyses, these structures reveal the organizational principles behind the hexameric MecA-ClpC complex, explain the molecular mechanisms for MecA-mediated ClpC activation and provide mechanistic insights into the function of the MecA-ClpC molecular machine. These findings have implications for related Clp/Hsp100 molecular machines.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Feng -- Mei, Ziqing -- Qi, Yutao -- Yan, Chuangye -- Hu, Qi -- Wang, Jiawei -- Shi, Yigong -- England -- Nature. 2011 Mar 17;471(7338):331-5. doi: 10.1038/nature09780. Epub 2011 Mar 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21368759" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Bacterial Proteins/*chemistry/genetics/*metabolism ; Binding Sites ; Crystallography, X-Ray ; Endopeptidase Clp/metabolism ; Heat-Shock Proteins/*chemistry/genetics/*metabolism ; Hydrolysis ; Models, Molecular ; Protein Binding ; Protein Conformation ; Protein Multimerization ; Protein Structure, Tertiary ; Protein Unfolding ; Substrate Specificity
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  • 75
    Publication Date: 2011-07-08
    Description: Swi2/Snf2-type ATPases regulate genome-associated processes such as transcription, replication and repair by catalysing the disruption, assembly or remodelling of nucleosomes or other protein-DNA complexes. It has been suggested that ATP-driven motor activity along DNA disrupts target protein-DNA interactions in the remodelling reaction. However, the complex and highly specific remodelling reactions are poorly understood, mostly because of a lack of high-resolution structural information about how remodellers bind to their substrate proteins. Mot1 (modifier of transcription 1 in Saccharomyces cerevisiae, denoted BTAF1 in humans) is a Swi2/Snf2 enzyme that specifically displaces the TATA box binding protein (TBP) from the promoter DNA and regulates transcription globally by generating a highly dynamic TBP pool in the cell. As a Swi2/Snf2 enzyme that functions as a single polypeptide and interacts with a relatively simple substrate, Mot1 offers an ideal system from which to gain a better understanding of this important enzyme family. To reveal how Mot1 specifically disrupts TBP-DNA complexes, we combined crystal and electron microscopy structures of Mot1-TBP from Encephalitozoon cuniculi with biochemical studies. Here we show that Mot1 wraps around TBP and seems to act like a bottle opener: a spring-like array of 16 HEAT (huntingtin, elongation factor 3, protein phosphatase 2A and lipid kinase TOR) repeats grips the DNA-distal side of TBP via loop insertions, and the Swi2/Snf2 domain binds to upstream DNA, positioned to weaken the TBP-DNA interaction by DNA translocation. A 'latch' subsequently blocks the DNA-binding groove of TBP, acting as a chaperone to prevent DNA re-association and ensure efficient promoter clearance. This work shows how a remodelling enzyme can combine both motor and chaperone activities to achieve functional specificity using a conserved Swi2/Snf2 translocase.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276066/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276066/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wollmann, Petra -- Cui, Sheng -- Viswanathan, Ramya -- Berninghausen, Otto -- Wells, Melissa N -- Moldt, Manuela -- Witte, Gregor -- Butryn, Agata -- Wendler, Petra -- Beckmann, Roland -- Auble, David T -- Hopfner, Karl-Peter -- GM55763/GM/NIGMS NIH HHS/ -- R01 GM055763/GM/NIGMS NIH HHS/ -- R01 GM055763-13/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 Jul 6;475(7356):403-7. doi: 10.1038/nature10215.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Ludwig-Maximilians University, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21734658" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Crystallization ; Crystallography, X-Ray ; DNA/chemistry/genetics/metabolism/ultrastructure ; Encephalitozoon cuniculi/*chemistry ; Fungal Proteins/*chemistry/*metabolism/ultrastructure ; Microscopy, Electron ; Models, Biological ; Models, Molecular ; Promoter Regions, Genetic/genetics ; Protein Conformation ; Protein Structure, Tertiary ; Structure-Activity Relationship ; Substrate Specificity ; TATA-Box Binding Protein/*chemistry/*metabolism/ultrastructure ; Transcription Factor TFIIB/chemistry/metabolism
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  • 76
    Publication Date: 2011-09-29
    Description: Transcription of the mitochondrial genome is performed by a single-subunit RNA polymerase (mtRNAP) that is distantly related to the RNAP of bacteriophage T7, the pol I family of DNA polymerases, and single-subunit RNAPs from chloroplasts. Whereas T7 RNAP can initiate transcription by itself, mtRNAP requires the factors TFAM and TFB2M for binding and melting promoter DNA. TFAM is an abundant protein that binds and bends promoter DNA 15-40 base pairs upstream of the transcription start site, and stimulates the recruitment of mtRNAP and TFB2M to the promoter. TFB2M assists mtRNAP in promoter melting and reaches the active site of mtRNAP to interact with the first base pair of the RNA-DNA hybrid. Here we report the X-ray structure of human mtRNAP at 2.5 A resolution, which reveals a T7-like catalytic carboxy-terminal domain, an amino-terminal domain that remotely resembles the T7 promoter-binding domain, a novel pentatricopeptide repeat domain, and a flexible N-terminal extension. The pentatricopeptide repeat domain sequesters an AT-rich recognition loop, which binds promoter DNA in T7 RNAP, probably explaining the need for TFAM during promoter binding. Consistent with this, substitution of a conserved arginine residue in the AT-rich recognition loop, or release of this loop by deletion of the N-terminal part of mtRNAP, had no effect on transcription. The fingers domain and the intercalating hairpin, which melts DNA in phage RNAPs, are repositioned, explaining the need for TFB2M during promoter melting. Our results provide a new venue for the mechanistic analysis of mitochondrial transcription. They also indicate how an early phage-like mtRNAP lost functions in promoter binding and melting, which were provided by initiation factors in trans during evolution, to enable mitochondrial gene regulation and the adaptation of mitochondrial function to changes in the environment.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ringel, Rieke -- Sologub, Marina -- Morozov, Yaroslav I -- Litonin, Dmitry -- Cramer, Patrick -- Temiakov, Dmitry -- England -- Nature. 2011 Sep 25;478(7368):269-73. doi: 10.1038/nature10435.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universitat Munchen, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21947009" target="_blank"〉PubMed〈/a〉
    Keywords: AT Rich Sequence/genetics ; Amino Acid Sequence ; Bacteriophage T7/enzymology ; Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; DNA/chemistry/genetics/metabolism ; DNA-Directed RNA Polymerases/*chemistry/metabolism ; Humans ; Hydrophobic and Hydrophilic Interactions ; Mitochondria/*enzymology ; Models, Molecular ; Molecular Sequence Data ; Nucleic Acid Denaturation ; Promoter Regions, Genetic/genetics ; Protein Structure, Tertiary ; Sequence Alignment ; Templates, Genetic ; Viral Proteins/chemistry
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  • 77
    Publication Date: 2011-10-04
    Description: Many replication initiators form higher-order oligomers that process host replication origins to promote replisome formation. In addition to dedicated duplex-DNA-binding domains, cellular initiators possess AAA+ (ATPases associated with various cellular activities) elements that drive functions ranging from protein assembly to origin recognition. In bacteria, the AAA+ domain of the initiator DnaA has been proposed to assist in single-stranded DNA formation during origin melting. Here we show crystallographically and in solution that the ATP-dependent assembly of Aquifex aeolicus DnaA into a spiral oligomer creates a continuous surface that allows successive AAA+ domains to bind and extend single-stranded DNA segments. The mechanism of binding is unexpectedly similar to that of RecA, a homologous recombination factor, but it differs in that DnaA promotes a nucleic acid conformation that prevents pairing of a complementary strand. These findings, combined with strand-displacement assays, indicate that DnaA opens replication origins by a direct ATP-dependent stretching mechanism. Comparative studies reveal notable commonalities between the approach used by DnaA to engage DNA substrates and other, nucleic-acid-dependent, AAA+ systems.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3192921/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3192921/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Duderstadt, Karl E -- Chuang, Kevin -- Berger, James M -- GM071747/GM/NIGMS NIH HHS/ -- R01 GM071747/GM/NIGMS NIH HHS/ -- R01 GM071747-06/GM/NIGMS NIH HHS/ -- T32 GM008295/GM/NIGMS NIH HHS/ -- England -- Nature. 2011 Oct 2;478(7368):209-13. doi: 10.1038/nature10455.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biophysics Graduate Group, University of California, Berkeley, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21964332" target="_blank"〉PubMed〈/a〉
    Keywords: AT Rich Sequence ; Adenosine Triphosphatases/metabolism ; Adenosine Triphosphate/metabolism ; Bacteria/enzymology/genetics ; Bacterial Proteins/chemistry/*metabolism ; Biocatalysis ; Crystallography, X-Ray ; DNA Replication ; DNA, Bacterial/*chemistry/genetics/*metabolism ; DNA, Single-Stranded/chemistry/genetics/metabolism ; DNA-Binding Proteins/chemistry/*metabolism ; DNA-Directed DNA Polymerase/metabolism ; Models, Molecular ; Molecular Conformation ; Multienzyme Complexes/metabolism ; *Nucleic Acid Conformation ; Nucleic Acid Denaturation ; Rec A Recombinases/chemistry ; *Replication Origin/genetics ; Substrate Specificity
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  • 78
    Publication Date: 2011-03-11
    Description: G-protein-coupled receptors (GPCRs) comprise the largest family of membrane proteins in the human genome and mediate cellular responses to an extensive array of hormones, neurotransmitters and sensory stimuli. Although some crystal structures have been determined for GPCRs, most are for modified forms, showing little basal activity, and are bound to inverse agonists or antagonists. Consequently, these structures correspond to receptors in their inactive states. The visual pigment rhodopsin is the only GPCR for which structures exist that are thought to be in the active state. However, these structures are for the apoprotein, or opsin, form that does not contain the agonist all-trans retinal. Here we present a crystal structure at a resolution of 3 A for the constitutively active rhodopsin mutant Glu 113 Gln in complex with a peptide derived from the carboxy terminus of the alpha-subunit of the G protein transducin. The protein is in an active conformation that retains retinal in the binding pocket after photoactivation. Comparison with the structure of ground-state rhodopsin suggests how translocation of the retinal beta-ionone ring leads to a rotation of transmembrane helix 6, which is the critical conformational change on activation. A key feature of this conformational change is a reorganization of water-mediated hydrogen-bond networks between the retinal-binding pocket and three of the most conserved GPCR sequence motifs. We thus show how an agonist ligand can activate its GPCR.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3715716/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3715716/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Standfuss, Jorg -- Edwards, Patricia C -- D'Antona, Aaron -- Fransen, Maikel -- Xie, Guifu -- Oprian, Daniel D -- Schertler, Gebhard F X -- EY007965/EY/NEI NIH HHS/ -- MC_U105178937/Medical Research Council/United Kingdom -- MC_U105197215/Medical Research Council/United Kingdom -- R01 EY007965/EY/NEI NIH HHS/ -- England -- Nature. 2011 Mar 31;471(7340):656-60. doi: 10.1038/nature09795. Epub 2011 Mar 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21389983" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Binding Sites ; Crystallization ; Crystallography, X-Ray ; HEK293 Cells ; Humans ; Hydrogen Bonding/drug effects ; Ligands ; Models, Molecular ; Peptide Fragments/chemistry/metabolism ; Protein Conformation/drug effects ; Retinaldehyde/chemistry/metabolism/pharmacology ; Rhodopsin/*agonists/*chemistry/genetics/metabolism ; Rotation ; Transducin/chemistry/metabolism ; Water/chemistry/metabolism
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  • 79
    Publication Date: 2011-08-26
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Buchen, Lizzie -- England -- Nature. 2011 Aug 24;476(7361):387-90. doi: 10.1038/476387a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21866135" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallization/history ; Crystallography, X-Ray ; History, 20th Century ; History, 21st Century ; Models, Molecular ; Receptors, G-Protein-Coupled/*chemistry/history/metabolism ; Signal Transduction
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  • 80
    Publication Date: 2011-07-08
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Robinson, Nigel J -- BB/H011110/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2011 Jul 6;475(7354):41-2. doi: 10.1038/475041a.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biophysical Sciences Institute, Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, UK. nigel.robinson@durham.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21734698" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphatases/genetics/metabolism ; Bacterial Proteins/*chemistry/*metabolism ; Biological Transport ; Cation Transport Proteins/genetics/metabolism ; Copper/*metabolism ; Crystallography, X-Ray ; Hepatolenticular Degeneration/enzymology/genetics/metabolism ; Humans ; Legionella pneumophila/*chemistry ; Menkes Kinky Hair Syndrome/enzymology/genetics ; Protein Structure, Tertiary ; Structure-Activity Relationship
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  • 81
    Publication Date: 2011-03-23
    Description: Inhibitor of kappaB (IkappaB) kinase (IKK) phosphorylates IkappaB proteins, leading to their degradation and the liberation of nuclear factor kappaB for gene transcription. Here we report the crystal structure of IKKbeta in complex with an inhibitor, at a resolution of 3.6 A. The structure reveals a trimodular architecture comprising the kinase domain, a ubiquitin-like domain (ULD) and an elongated, alpha-helical scaffold/dimerization domain (SDD). Unexpectedly, the predicted leucine zipper and helix-loop-helix motifs do not form these structures but are part of the SDD. The ULD and SDD mediate a critical interaction with IkappaBalpha that restricts substrate specificity, and the ULD is also required for catalytic activity. The SDD mediates IKKbeta dimerization, but dimerization per se is not important for maintaining IKKbeta activity and instead is required for IKKbeta activation. Other IKK family members, IKKalpha, TBK1 and IKK-i, may have a similar trimodular architecture and function.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081413/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081413/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xu, Guozhou -- Lo, Yu-Chih -- Li, Qiubai -- Napolitano, Gennaro -- Wu, Xuefeng -- Jiang, Xuliang -- Dreano, Michel -- Karin, Michael -- Wu, Hao -- R01 AI050872/AI/NIAID NIH HHS/ -- R01 AI050872-10/AI/NIAID NIH HHS/ -- R01 AI079260/AI/NIAID NIH HHS/ -- England -- Nature. 2011 Apr 21;472(7343):325-30. doi: 10.1038/nature09853. Epub 2011 Mar 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Weill Cornell Medical College, New York, New York 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21423167" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Animals ; Biocatalysis ; Crystallography, X-Ray ; Enzyme Activation ; Humans ; I-kappa B Kinase/*antagonists & inhibitors/*chemistry/metabolism ; Models, Molecular ; Protein Binding ; Protein Multimerization ; Protein Structure, Tertiary ; Substrate Specificity ; Ubiquitin/chemistry ; Xenopus laevis
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  • 82
    Publication Date: 2011-09-20
    Description: Dynamin is a mechanochemical GTPase that oligomerizes around the neck of clathrin-coated pits and catalyses vesicle scission in a GTP-hydrolysis-dependent manner. The molecular details of oligomerization and the mechanism of the mechanochemical coupling are currently unknown. Here we present the crystal structure of human dynamin 1 in the nucleotide-free state with a four-domain architecture comprising the GTPase domain, the bundle signalling element, the stalk and the pleckstrin homology domain. Dynamin 1 oligomerized in the crystals via the stalks, which assemble in a criss-cross fashion. The stalks further interact via conserved surfaces with the pleckstrin homology domain and the bundle signalling element of the neighbouring dynamin molecule. This intricate domain interaction rationalizes a number of disease-related mutations in dynamin 2 and suggests a structural model for the mechanochemical coupling that reconciles previous models of dynamin function.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Faelber, Katja -- Posor, York -- Gao, Song -- Held, Martin -- Roske, Yvette -- Schulze, Dennis -- Haucke, Volker -- Noe, Frank -- Daumke, Oliver -- England -- Nature. 2011 Sep 18;477(7366):556-60. doi: 10.1038/nature10369.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Crystallography, Max-Delbruck-Centrum for Molecular Medicine, Robert-Rossle-Strasse 10, 13125 Berlin, Germany. katja.faelber@mdc-berlin.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21927000" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallography, X-Ray ; Dynamin I/*chemistry/metabolism ; Dynamin II/genetics/metabolism ; GTP Phosphohydrolases/chemistry/metabolism ; Guanosine Triphosphate/metabolism ; HeLa Cells ; Humans ; Hydrolysis ; Models, Molecular ; Molecular Dynamics Simulation ; *Nucleotides ; Protein Binding ; Protein Structure, Tertiary ; Signal Transduction ; Transferrin/metabolism
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  • 83
    Publication Date: 2012-03-16
    Description: Derivatives of vitamin B(12) are used in methyl group transfer in biological processes as diverse as methionine synthesis in humans and CO(2) fixation in acetogenic bacteria. This seemingly straightforward reaction requires large, multimodular enzyme complexes that adopt multiple conformations to alternately activate, protect and perform catalysis on the reactive B(12) cofactor. Crystal structures determined thus far have provided structural information for only fragments of these complexes, inspiring speculation about the overall protein assembly and conformational movements inherent to activity. Here we present X-ray crystal structures of a complete 220 kDa complex that contains all enzymes responsible for B(12)-dependent methyl transfer, namely the corrinoid iron-sulphur protein and its methyltransferase from the model acetogen Moorella thermoacetica. These structures provide the first three-dimensional depiction of all protein modules required for the activation, protection and catalytic steps of B(12)-dependent methyl transfer. In addition, the structures capture B(12) at multiple locations between its 'resting' and catalytic positions, allowing visualization of the dramatic protein rearrangements that enable methyl transfer and identification of the trajectory for B(12) movement within the large enzyme scaffold. The structures are also presented alongside in crystallo spectroscopic data, which confirm enzymatic activity within crystals and demonstrate the largest known conformational movements of proteins in a crystalline state. Taken together, this work provides a model for the molecular juggling that accompanies turnover and helps explain why such an elaborate protein framework is required for such a simple, yet biologically essential reaction.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3326194/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3326194/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kung, Yan -- Ando, Nozomi -- Doukov, Tzanko I -- Blasiak, Leah C -- Bender, Gunes -- Seravalli, Javier -- Ragsdale, Stephen W -- Drennan, Catherine L -- GM39451/GM/NIGMS NIH HHS/ -- GM69857/GM/NIGMS NIH HHS/ -- R01 GM039451/GM/NIGMS NIH HHS/ -- R01 GM039451-25/GM/NIGMS NIH HHS/ -- R01 GM069857/GM/NIGMS NIH HHS/ -- R37 GM039451/GM/NIGMS NIH HHS/ -- RR-15301/RR/NCRR NIH HHS/ -- T32 GM008334/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Mar 14;484(7393):265-9. doi: 10.1038/nature10916.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22419154" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Biocatalysis ; Corrinoids/metabolism ; Crystallography, X-Ray ; Folic Acid/metabolism ; Iron-Sulfur Proteins/*chemistry/*metabolism ; Methylation ; Methyltransferases/*chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Moorella/chemistry/*enzymology ; Protein Multimerization ; Protein Structure, Tertiary ; Vitamin B 12/*metabolism
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  • 84
    Publication Date: 2012-07-31
    Description: Acid-sensing ion channels (ASICs) are voltage-independent, amiloride-sensitive channels involved in diverse physiological processes ranging from nociception to taste. Despite the importance of ASICs in physiology, we know little about the mechanism of channel activation. Here we show that psalmotoxin activates non-selective and Na(+)-selective currents in chicken ASIC1a at pH 7.25 and 5.5, respectively. Crystal structures of ASIC1a-psalmotoxin complexes map the toxin binding site to the extracellular domain and show how toxin binding triggers an expansion of the extracellular vestibule and stabilization of the open channel pore. At pH 7.25 the pore is approximately 10 A in diameter, whereas at pH 5.5 the pore is largely hydrophobic and elliptical in cross-section with dimensions of approximately 5 by 7 A, consistent with a barrier mechanism for ion selectivity. These studies define mechanisms for activation of ASICs, illuminate the basis for dynamic ion selectivity and provide the blueprints for new therapeutic agents.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725952/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725952/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Baconguis, Isabelle -- Gouaux, Eric -- F31 NS070597/NS/NINDS NIH HHS/ -- P30 NS061800/NS/NINDS NIH HHS/ -- R37 NS038631/NS/NINDS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Sep 20;489(7416):400-5. doi: 10.1038/nature11375. Epub 2012 Jul 29.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22842900" target="_blank"〉PubMed〈/a〉
    Keywords: Acid Sensing Ion Channels ; Animals ; Binding Sites ; CHO Cells ; Cations, Monovalent/metabolism ; Cesium/metabolism ; Chickens ; Cricetinae ; Crystallography, X-Ray ; Hydrogen-Ion Concentration ; Ion Channel Gating/*drug effects ; Models, Molecular ; Nerve Tissue Proteins/*chemistry/genetics/*metabolism ; Protein Conformation ; Protein Subunits/chemistry/metabolism ; Sequence Deletion ; Sodium/metabolism/pharmacology ; Sodium Channels/*chemistry/genetics/*metabolism ; Spider Venoms/*chemistry/metabolism/*pharmacology ; Spiders/chemistry ; Substrate Specificity/drug effects
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  • 85
    Publication Date: 2012-10-23
    Description: The single-component type-II NADH dehydrogenases (NDH-2s) serve as alternatives to the multisubunit respiratory complex I (type-I NADH dehydrogenase (NDH-1), also called NADH:ubiquinone oxidoreductase; EC 1.6.5.3) in catalysing electron transfer from NADH to ubiquinone in the mitochondrial respiratory chain. The yeast NDH-2 (Ndi1) oxidizes NADH on the matrix side and reduces ubiquinone to maintain mitochondrial NADH/NAD(+) homeostasis. Ndi1 is a potential therapeutic agent for human diseases caused by complex I defects, particularly Parkinson's disease, because its expression restores the mitochondrial activity in animals with complex I deficiency. NDH-2s in pathogenic microorganisms are viable targets for new antibiotics. Here we solve the crystal structures of Ndi1 in its substrate-free, NADH-, ubiquinone- and NADH-ubiquinone-bound states, to help understand the catalytic mechanism of NDH-2s. We find that Ndi1 homodimerization through its carboxy-terminal domain is critical for its catalytic activity and membrane targeting. The structures reveal two ubiquinone-binding sites (UQ(I) and UQ(II)) in Ndi1. NADH and UQ(I) can bind to Ndi1 simultaneously to form a substrate-protein complex. We propose that UQ(I) interacts with FAD to act as an intermediate for electron transfer, and that NADH transfers electrons through this FAD-UQ(I) complex to UQ(II). Together our data reveal the regulatory and catalytic mechanisms of Ndi1 and may facilitate the development or targeting of NDH-2s for potential therapeutic applications.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Feng, Yue -- Li, Wenfei -- Li, Jian -- Wang, Jiawei -- Ge, Jingpeng -- Xu, Duo -- Liu, Yanjing -- Wu, Kaiqi -- Zeng, Qingyin -- Wu, Jia-Wei -- Tian, Changlin -- Zhou, Bing -- Yang, Maojun -- England -- Nature. 2012 Nov 15;491(7424):478-82. doi: 10.1038/nature11541. Epub 2012 Oct 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23086143" target="_blank"〉PubMed〈/a〉
    Keywords: Crystallography, X-Ray ; Electron Transport Complex I/*chemistry/isolation & purification/metabolism ; Mitochondria/*enzymology ; *Models, Molecular ; NAD/chemistry ; Protein Binding ; Protein Multimerization ; Protein Structure, Tertiary ; Saccharomyces cerevisiae/chemistry/enzymology ; Saccharomyces cerevisiae Proteins/*chemistry/isolation & purification/metabolism ; Ubiquinone/chemistry
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  • 86
    Publication Date: 2012-03-23
    Description: Opioid receptors mediate the actions of endogenous and exogenous opioids on many physiological processes, including the regulation of pain, respiratory drive, mood, and--in the case of kappa-opioid receptor (kappa-OR)--dysphoria and psychotomimesis. Here we report the crystal structure of the human kappa-OR in complex with the selective antagonist JDTic, arranged in parallel dimers, at 2.9 A resolution. The structure reveals important features of the ligand-binding pocket that contribute to the high affinity and subtype selectivity of JDTic for the human kappa-OR. Modelling of other important kappa-OR-selective ligands, including the morphinan-derived antagonists norbinaltorphimine and 5'-guanidinonaltrindole, and the diterpene agonist salvinorin A analogue RB-64, reveals both common and distinct features for binding these diverse chemotypes. Analysis of site-directed mutagenesis and ligand structure-activity relationships confirms the interactions observed in the crystal structure, thereby providing a molecular explanation for kappa-OR subtype selectivity, and essential insights for the design of compounds with new pharmacological properties targeting the human kappa-OR.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356457/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356457/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wu, Huixian -- Wacker, Daniel -- Mileni, Mauro -- Katritch, Vsevolod -- Han, Gye Won -- Vardy, Eyal -- Liu, Wei -- Thompson, Aaron A -- Huang, Xi-Ping -- Carroll, F Ivy -- Mascarella, S Wayne -- Westkaemper, Richard B -- Mosier, Philip D -- Roth, Bryan L -- Cherezov, Vadim -- Stevens, Raymond C -- P50 GM073197/GM/NIGMS NIH HHS/ -- P50 GM073197-08/GM/NIGMS NIH HHS/ -- R01 DA009045/DA/NIDA NIH HHS/ -- R01 DA009045-17/DA/NIDA NIH HHS/ -- R01 DA017204/DA/NIDA NIH HHS/ -- R01 DA017624/DA/NIDA NIH HHS/ -- R01 DA027170/DA/NIDA NIH HHS/ -- U54 GM094618/GM/NIGMS NIH HHS/ -- U54 GM094618-02/GM/NIGMS NIH HHS/ -- Y1-CO-1020/CO/NCI NIH HHS/ -- Y1-GM-1104/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Mar 21;485(7398):327-32. doi: 10.1038/nature10939.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22437504" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Crystallography, X-Ray ; Diterpenes, Clerodane/chemistry/metabolism/pharmacology ; Guanidines/chemistry ; Humans ; Models, Molecular ; Morphinans/chemistry ; Mutagenesis, Site-Directed ; Naltrexone/analogs & derivatives/chemistry/metabolism ; Piperidines/*chemistry/pharmacology ; Protein Conformation ; Receptors, Adrenergic, beta-2/chemistry ; Receptors, CXCR4/chemistry/metabolism ; Receptors, Opioid, kappa/*antagonists & inhibitors/*chemistry/genetics/metabolism ; Structure-Activity Relationship ; Tetrahydroisoquinolines/*chemistry/pharmacology
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  • 87
    Publication Date: 2012-10-19
    Description: Glucose transporters are essential for metabolism of glucose in cells of diverse organisms from microbes to humans, exemplified by the disease-related human proteins GLUT1, 2, 3 and 4. Despite rigorous efforts, the structural information for GLUT1-4 or their homologues remains largely unknown. Here we report three related crystal structures of XylE, an Escherichia coli homologue of GLUT1-4, in complex with d-xylose, d-glucose and 6-bromo-6-deoxy-D-glucose, at resolutions of 2.8, 2.9 and 2.6 A, respectively. The structure consists of a typical major facilitator superfamily fold of 12 transmembrane segments and a unique intracellular four-helix domain. XylE was captured in an outward-facing, partly occluded conformation. Most of the important amino acids responsible for recognition of D-xylose or d-glucose are invariant in GLUT1-4, suggesting functional and mechanistic conservations. Structure-based modelling of GLUT1-4 allows mapping and interpretation of disease-related mutations. The structural and biochemical information reported here constitutes an important framework for mechanistic understanding of glucose transporters and sugar porters in general.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Linfeng -- Zeng, Xin -- Yan, Chuangye -- Sun, Xiuyun -- Gong, Xinqi -- Rao, Yu -- Yan, Nieng -- England -- Nature. 2012 Oct 18;490(7420):361-6. doi: 10.1038/nature11524.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Bio-membrane and Membrane Biotechnology, Center for Structural Biology, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23075985" target="_blank"〉PubMed〈/a〉
    Keywords: Biological Transport ; Crystallography, X-Ray ; Deoxyglucose/analogs & derivatives/chemistry/metabolism ; Escherichia coli/*chemistry ; Escherichia coli Proteins/*chemistry/metabolism ; Glucose/chemistry/metabolism ; Glucose Transport Proteins, Facilitative/*chemistry/metabolism ; Glucose Transporter Type 1/chemistry ; Humans ; Hydrogen Bonding ; Models, Molecular ; Protein Conformation ; Structural Homology, Protein ; Structure-Activity Relationship ; Substrate Specificity ; Symporters/*chemistry/metabolism ; Xylose/chemistry/metabolism
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  • 88
    Publication Date: 2012-06-23
    Description: The RNA-induced silencing complex, comprising Argonaute and guide RNA, mediates RNA interference. Here we report the 3.2 A crystal structure of Kluyveromyces polysporus Argonaute (KpAGO) fortuitously complexed with guide RNA originating from small-RNA duplexes autonomously loaded by recombinant KpAGO. Despite their diverse sequences, guide-RNA nucleotides 1-8 are positioned similarly, with sequence-independent contacts to bases, phosphates and 2'-hydroxyl groups pre-organizing the backbone of nucleotides 2-8 in a near-A-form conformation. Compared with prokaryotic Argonautes, KpAGO has numerous surface-exposed insertion segments, with a cluster of conserved insertions repositioning the N domain to enable full propagation of guide-target pairing. Compared with Argonautes in inactive conformations, KpAGO has a hydrogen-bond network that stabilizes an expanded and repositioned loop, which inserts an invariant glutamate into the catalytic pocket. Mutation analyses and analogies to ribonuclease H indicate that insertion of this glutamate finger completes a universally conserved catalytic tetrad, thereby activating Argonaute for RNA cleavage.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853139/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853139/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nakanishi, Kotaro -- Weinberg, David E -- Bartel, David P -- Patel, Dinshaw J -- AI068776/AI/NIAID NIH HHS/ -- GM61835/GM/NIGMS NIH HHS/ -- R01 AI068776/AI/NIAID NIH HHS/ -- R01 GM061835/GM/NIGMS NIH HHS/ -- R37 GM061835/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Jun 20;486(7403):368-74. doi: 10.1038/nature11211.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22722195" target="_blank"〉PubMed〈/a〉
    Keywords: Argonaute Proteins/*chemistry/*metabolism ; Base Sequence ; Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; Eukaryotic Cells/chemistry/enzymology ; Fungal Proteins/*chemistry/*metabolism ; Kluyveromyces/*chemistry/enzymology ; Models, Molecular ; Molecular Conformation ; Molecular Sequence Data ; RNA, Guide/*chemistry/genetics/*metabolism ; Saccharomycetales/enzymology/genetics
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  • 89
    Publication Date: 2012-05-19
    Description: Members of the opioid receptor family of G-protein-coupled receptors (GPCRs) are found throughout the peripheral and central nervous system, where they have key roles in nociception and analgesia. Unlike the 'classical' opioid receptors, delta, kappa and mu (delta-OR, kappa-OR and mu-OR), which were delineated by pharmacological criteria in the 1970s and 1980s, the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP, also known as ORL-1) was discovered relatively recently by molecular cloning and characterization of an orphan GPCR. Although it shares high sequence similarity with classical opioid GPCR subtypes ( approximately 60%), NOP has a markedly distinct pharmacology, featuring activation by the endogenous peptide N/OFQ, and unique selectivity for exogenous ligands. Here we report the crystal structure of human NOP, solved in complex with the peptide mimetic antagonist compound-24 (C-24) (ref. 4), revealing atomic details of ligand-receptor recognition and selectivity. Compound-24 mimics the first four amino-terminal residues of the NOP-selective peptide antagonist UFP-101, a close derivative of N/OFQ, and provides important clues to the binding of these peptides. The X-ray structure also shows substantial conformational differences in the pocket regions between NOP and the classical opioid receptors kappa (ref. 5) and mu (ref. 6), and these are probably due to a small number of residues that vary between these receptors. The NOP-compound-24 structure explains the divergent selectivity profile of NOP and provides a new structural template for the design of NOP ligands.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356928/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356928/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thompson, Aaron A -- Liu, Wei -- Chun, Eugene -- Katritch, Vsevolod -- Wu, Huixian -- Vardy, Eyal -- Huang, Xi-Ping -- Trapella, Claudio -- Guerrini, Remo -- Calo, Girolamo -- Roth, Bryan L -- Cherezov, Vadim -- Stevens, Raymond C -- P50 GM073197/GM/NIGMS NIH HHS/ -- P50 GM073197-08/GM/NIGMS NIH HHS/ -- R01 DA017204/DA/NIDA NIH HHS/ -- R01 DA017204-08/DA/NIDA NIH HHS/ -- R01 DA027170/DA/NIDA NIH HHS/ -- R01 DA027170-03/DA/NIDA NIH HHS/ -- R01 DA27170/DA/NIDA NIH HHS/ -- U54 GM094618/GM/NIGMS NIH HHS/ -- U54 GM094618-02/GM/NIGMS NIH HHS/ -- Y1-CO-1020/CO/NCI NIH HHS/ -- Y1-GM-1104/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 May 16;485(7398):395-9. doi: 10.1038/nature11085.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22596163" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Biomimetic Materials/*chemistry/metabolism/pharmacology ; Crystallography, X-Ray ; HEK293 Cells ; Humans ; Ligands ; Models, Molecular ; Narcotic Antagonists ; Opioid Peptides/*chemistry/metabolism/pharmacology ; Piperidines/*chemistry/*metabolism/pharmacology ; Protein Conformation ; Receptors, Opioid/*chemistry/*metabolism ; Receptors, Opioid, kappa/chemistry/metabolism ; Spiro Compounds/*chemistry/*metabolism/pharmacology ; Substrate Specificity
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  • 90
    Publication Date: 2012-06-09
    Description: Voltage-gated sodium (Na(v)) channels are essential for the rapid depolarization of nerve and muscle, and are important drug targets. Determination of the structures of Na(v) channels will shed light on ion channel mechanisms and facilitate potential clinical applications. A family of bacterial Na(v) channels, exemplified by the Na(+)-selective channel of bacteria (NaChBac), provides a useful model system for structure-function analysis. Here we report the crystal structure of Na(v)Rh, a NaChBac orthologue from the marine alphaproteobacterium HIMB114 (Rickettsiales sp. HIMB114; denoted Rh), at 3.05 A resolution. The channel comprises an asymmetric tetramer. The carbonyl oxygen atoms of Thr 178 and Leu 179 constitute an inner site within the selectivity filter where a hydrated Ca(2+) resides in the crystal structure. The outer mouth of the Na(+) selectivity filter, defined by Ser 181 and Glu 183, is closed, as is the activation gate at the intracellular side of the pore. The voltage sensors adopt a depolarized conformation in which all the gating charges are exposed to the extracellular environment. We propose that Na(v)Rh is in an 'inactivated' conformation. Comparison of Na(v)Rh with Na(v)Ab reveals considerable conformational rearrangements that may underlie the electromechanical coupling mechanism of voltage-gated channels.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3979295/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3979295/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Xu -- Ren, Wenlin -- DeCaen, Paul -- Yan, Chuangye -- Tao, Xiao -- Tang, Lin -- Wang, Jingjing -- Hasegawa, Kazuya -- Kumasaka, Takashi -- He, Jianhua -- Wang, Jiawei -- Clapham, David E -- Yan, Nieng -- P01 NS072040/NS/NINDS NIH HHS/ -- T32 HL007572/HL/NHLBI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 May 20;486(7401):130-4. doi: 10.1038/nature11054.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Bio-membrane and Membrane Biotechnology, Center for Structural Biology, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22678295" target="_blank"〉PubMed〈/a〉
    Keywords: Alphaproteobacteria/*chemistry ; Amino Acid Sequence ; Bacterial Proteins/*chemistry/metabolism ; Crystallization ; Crystallography, X-Ray ; HEK293 Cells ; Humans ; *Ion Channel Gating ; Models, Molecular ; Molecular Sequence Data ; Protein Conformation ; Sodium Channels/*chemistry/metabolism ; Structure-Activity Relationship
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  • 91
    Publication Date: 2012-02-14
    Description: Menin is a tumour suppressor protein whose loss or inactivation causes multiple endocrine neoplasia 1 (MEN1), a hereditary autosomal dominant tumour syndrome that is characterized by tumorigenesis in multiple endocrine organs. Menin interacts with many proteins and is involved in a variety of cellular processes. Menin binds the JUN family transcription factor JUND and inhibits its transcriptional activity. Several MEN1 missense mutations disrupt the menin-JUND interaction, suggesting a correlation between the tumour-suppressor function of menin and its suppression of JUND-activated transcription. Menin also interacts with mixed lineage leukaemia protein 1 (MLL1), a histone H3 lysine 4 methyltransferase, and functions as an oncogenic cofactor to upregulate gene transcription and promote MLL1-fusion-protein-induced leukaemogenesis. A recent report on the tethering of MLL1 to chromatin binding factor lens epithelium-derived growth factor (LEDGF) by menin indicates that menin is a molecular adaptor coordinating the functions of multiple proteins. Despite its importance, how menin interacts with many distinct partners and regulates their functions remains poorly understood. Here we present the crystal structures of human menin in its free form and in complexes with MLL1 or with JUND, or with an MLL1-LEDGF heterodimer. These structures show that menin contains a deep pocket that binds short peptides of MLL1 or JUND in the same manner, but that it can have opposite effects on transcription. The menin-JUND interaction blocks JUN N-terminal kinase (JNK)-mediated JUND phosphorylation and suppresses JUND-induced transcription. In contrast, menin promotes gene transcription by binding the transcription activator MLL1 through the peptide pocket while still interacting with the chromatin-anchoring protein LEDGF at a distinct surface formed by both menin and MLL1.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983792/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983792/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Jing -- Gurung, Buddha -- Wan, Bingbing -- Matkar, Smita -- Veniaminova, Natalia A -- Wan, Ke -- Merchant, Juanita L -- Hua, Xianxin -- Lei, Ming -- GM083015-01/GM/NIGMS NIH HHS/ -- R01 DK085121/DK/NIDDK NIH HHS/ -- R01-DK085121/DK/NIDDK NIH HHS/ -- R37 DK045729/DK/NIDDK NIH HHS/ -- R37-DK45729/DK/NIDDK NIH HHS/ -- Y1-CO-1020/CO/NCI NIH HHS/ -- Y1-GM-1104/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Feb 12;482(7386):542-6. doi: 10.1038/nature10806.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22327296" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Amino Acid Sequence ; Animals ; Binding Sites ; Chromatin/metabolism ; Crystallography, X-Ray ; Fibroblasts ; HEK293 Cells ; Histone-Lysine N-Methyltransferase ; Humans ; Intercellular Signaling Peptides and Proteins/metabolism ; JNK Mitogen-Activated Protein Kinases/metabolism ; Mice ; Models, Molecular ; Molecular Sequence Data ; Myeloid-Lymphoid Leukemia Protein/chemistry/*metabolism ; Phosphorylation ; Protein Binding ; Protein Multimerization ; Proto-Oncogene Proteins/*chemistry/*metabolism ; Proto-Oncogene Proteins c-jun/chemistry/*metabolism ; Structure-Activity Relationship ; *Transcription, Genetic
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  • 92
    Publication Date: 2012-03-13
    Description: Many bacterial pathogens can enter various host cells and then survive intracellularly, transiently evade humoral immunity, and further disseminate to other cells and tissues. When bacteria enter host cells and replicate intracellularly, the host cells sense the invading bacteria as damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) by way of various pattern recognition receptors. As a result, the host cells induce alarm signals that activate the innate immune system. Therefore, bacteria must modulate host inflammatory signalling and dampen these alarm signals. How pathogens do this after invading epithelial cells remains unclear, however. Here we show that OspI, a Shigella flexneri effector encoded by ORF169b on the large plasmid and delivered by the type IotaIotaIota secretion system, dampens acute inflammatory responses during bacterial invasion by suppressing the tumour-necrosis factor (TNF)-receptor-associated factor 6 (TRAF6)-mediated signalling pathway. OspI is a glutamine deamidase that selectively deamidates the glutamine residue at position 100 in UBC13 to a glutamic acid residue. Consequently, the E2 ubiquitin-conjugating activity required for TRAF6 activation is inhibited, allowing S. flexneri OspI to modulate the diacylglycerol-CBM (CARD-BCL10-MALT1) complex-TRAF6-nuclear-factor-kappaB signalling pathway. We determined the 2.0 A crystal structure of OspI, which contains a putative cysteine-histidine-aspartic acid catalytic triad. A mutational analysis showed this catalytic triad to be essential for the deamidation of UBC13. Our results suggest that S. flexneri inhibits acute inflammatory responses in the initial stage of infection by targeting the UBC13-TRAF6 complex.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sanada, Takahito -- Kim, Minsoo -- Mimuro, Hitomi -- Suzuki, Masato -- Ogawa, Michinaga -- Oyama, Akiho -- Ashida, Hiroshi -- Kobayashi, Taira -- Koyama, Tomohiro -- Nagai, Shinya -- Shibata, Yuri -- Gohda, Jin -- Inoue, Jun-ichiro -- Mizushima, Tsunehiro -- Sasakawa, Chihiro -- England -- Nature. 2012 Mar 11;483(7391):623-6. doi: 10.1038/nature10894.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Infectious Disease Control, International Research Center for Infectious Diseases, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22407319" target="_blank"〉PubMed〈/a〉
    Keywords: *Adaptor Proteins, Signal Transducing/metabolism ; Amidohydrolases/*chemistry/genetics/*metabolism ; Amino Acid Sequence ; Animals ; Aspartic Acid/metabolism ; Biocatalysis ; Caspases/metabolism ; Catalytic Domain/genetics ; Crystallography, X-Ray ; Cysteine/metabolism ; DNA Mutational Analysis ; Diglycerides/antagonists & inhibitors/metabolism ; Dysentery, Bacillary/microbiology ; Glutamic Acid/metabolism ; Glutamine/metabolism ; HEK293 Cells ; HeLa Cells ; Histidine/metabolism ; Humans ; Immunity, Innate ; Inflammation/enzymology/*immunology/*metabolism ; Mice ; Models, Molecular ; Molecular Sequence Data ; NF-kappa B/metabolism ; Neoplasm Proteins/metabolism ; Shigella flexneri/*enzymology/genetics/*immunology/pathogenicity ; TNF Receptor-Associated Factor 6/deficiency/genetics/metabolism ; Ubiquitin-Conjugating Enzymes/chemistry/genetics/*metabolism ; Virulence Factors/metabolism
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  • 93
    Publication Date: 2012-12-12
    Description: Protease-activated receptor 1 (PAR1) is the prototypical member of a family of G-protein-coupled receptors that mediate cellular responses to thrombin and related proteases. Thrombin irreversibly activates PAR1 by cleaving the amino-terminal exodomain of the receptor, which exposes a tethered peptide ligand that binds the heptahelical bundle of the receptor to affect G-protein activation. Here we report the 2.2 A resolution crystal structure of human PAR1 bound to vorapaxar, a PAR1 antagonist. The structure reveals an unusual mode of drug binding that explains how a small molecule binds virtually irreversibly to inhibit receptor activation by the tethered ligand of PAR1. In contrast to deep, solvent-exposed binding pockets observed in other peptide-activated G-protein-coupled receptors, the vorapaxar-binding pocket is superficial but has little surface exposed to the aqueous solvent. Protease-activated receptors are important targets for drug development. The structure reported here will aid the development of improved PAR1 antagonists and the discovery of antagonists to other members of this receptor family.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531875/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531875/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Cheng -- Srinivasan, Yoga -- Arlow, Daniel H -- Fung, Juan Jose -- Palmer, Daniel -- Zheng, Yaowu -- Green, Hillary F -- Pandey, Anjali -- Dror, Ron O -- Shaw, David E -- Weis, William I -- Coughlin, Shaun R -- Kobilka, Brian K -- HL44907/HL/NHLBI NIH HHS/ -- HL65590/HL/NHLBI NIH HHS/ -- NS028471/NS/NINDS NIH HHS/ -- R01 HL044907/HL/NHLBI NIH HHS/ -- R01 HL065185/HL/NHLBI NIH HHS/ -- R01 HL065590/HL/NHLBI NIH HHS/ -- England -- Nature. 2012 Dec 20;492(7429):387-92. doi: 10.1038/nature11701. Epub 2012 Dec 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23222541" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Binding Sites ; Crystallization ; Crystallography, X-Ray ; Enzyme Activation/genetics ; Humans ; Hydrolysis ; Lactones/chemistry/pharmacology ; Ligands ; Models, Molecular ; Molecular Dynamics Simulation ; Myocardial Infarction/prevention & control ; Protein Conformation ; Pyridines/chemistry/pharmacology ; Receptor, PAR-1/agonists/antagonists & inhibitors/*chemistry/metabolism ; Receptors, G-Protein-Coupled/chemistry/classification ; Receptors, Thrombin
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  • 94
    Publication Date: 2012-02-14
    Description: Neisseria are obligate human pathogens causing bacterial meningitis, septicaemia and gonorrhoea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are how human transferrin is specifically targeted, and how the bacteria liberate iron from transferrin at neutral pH. To address these questions, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small-angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3292680/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3292680/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Noinaj, Nicholas -- Easley, Nicole C -- Oke, Muse -- Mizuno, Naoko -- Gumbart, James -- Boura, Evzen -- Steere, Ashley N -- Zak, Olga -- Aisen, Philip -- Tajkhorshid, Emad -- Evans, Robert W -- Gorringe, Andrew R -- Mason, Anne B -- Steven, Alasdair C -- Buchanan, Susan K -- P41 RR005969/RR/NCRR NIH HHS/ -- P41-RR05969/RR/NCRR NIH HHS/ -- R01 GM086749/GM/NIGMS NIH HHS/ -- R01-DK21739/DK/NIDDK NIH HHS/ -- R01-GM086749/GM/NIGMS NIH HHS/ -- U54 GM087519/GM/NIGMS NIH HHS/ -- U54-GM087519/GM/NIGMS NIH HHS/ -- ZIA DK036143-04/Intramural NIH HHS/ -- England -- Nature. 2012 Feb 12;483(7387):53-8. doi: 10.1038/nature10823.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22327295" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Apoproteins/chemistry/metabolism ; Bacterial Proteins/*chemistry/metabolism/ultrastructure ; Binding Sites ; Biological Transport ; Cattle ; Crystallography, X-Ray ; Humans ; Iron/*metabolism ; Mice ; Models, Molecular ; Molecular Dynamics Simulation ; Neisseria/*metabolism/pathogenicity ; Protein Conformation ; Scattering, Small Angle ; Species Specificity ; Structure-Activity Relationship ; Transferrin/chemistry/metabolism/ultrastructure ; Transferrin-Binding Protein A/*chemistry/*metabolism/ultrastructure ; Transferrin-Binding Protein B/*chemistry/*metabolism/ultrastructure ; X-Ray Diffraction
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  • 95
    Publication Date: 2012-07-06
    Description: Cytochrome c oxidase is a member of the haem copper oxidase superfamily (HCO). HCOs function as the terminal enzymes in the respiratory chain of mitochondria and aerobic prokaryotes, coupling molecular oxygen reduction to transmembrane proton pumping. Integral to the enzyme's function is the transfer of electrons from cytochrome c to the oxidase via a transient association of the two proteins. Electron entry and exit are proposed to occur from the same site on cytochrome c. Here we report the crystal structure of the caa3-type cytochrome oxidase from Thermus thermophilus, which has a covalently tethered cytochrome c domain. Crystals were grown in a bicontinuous mesophase using a synthetic short-chain monoacylglycerol as the hosting lipid. From the electron density map, at 2.36 A resolution, a novel integral membrane subunit and a native glycoglycerophospholipid embedded in the complex were identified. Contrary to previous electron transfer mechanisms observed for soluble cytochrome c, the structure reveals the architecture of the electron transfer complex for the fused cupredoxin/cytochrome c domain, which implicates different sites on cytochrome c for electron entry and exit. Support for an alternative to the classical proton gate characteristic of this HCO class is presented.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428721/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428721/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lyons, Joseph A -- Aragao, David -- Slattery, Orla -- Pisliakov, Andrei V -- Soulimane, Tewfik -- Caffrey, Martin -- GM75915/GM/NIGMS NIH HHS/ -- P50 GM073210/GM/NIGMS NIH HHS/ -- P50GM073210/GM/NIGMS NIH HHS/ -- R01 GM061070/GM/NIGMS NIH HHS/ -- R01 GM075915/GM/NIGMS NIH HHS/ -- U54 GM094599/GM/NIGMS NIH HHS/ -- U54GM094599/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Jul 26;487(7408):514-8. doi: 10.1038/nature11182.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22763450" target="_blank"〉PubMed〈/a〉
    Keywords: Azurin/metabolism ; Catalytic Domain ; Cell Membrane/metabolism ; Crystallization ; Crystallography, X-Ray ; Cytochrome c Group/*metabolism ; Cytochromes a/*metabolism ; Cytochromes a3/*metabolism ; Electron Transport ; Electron Transport Complex IV/*chemistry/*metabolism ; Electrons ; Glycerophospholipids/chemistry/metabolism ; Models, Molecular ; Oxygen/metabolism ; Protein Structure, Tertiary ; Protein Subunits/chemistry/metabolism ; Protons ; Thermus thermophilus/*enzymology ; Water/chemistry/metabolism
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  • 96
    Publication Date: 2012-04-17
    Description: As with many other viruses, the initial cell attachment of rotaviruses, which are the major causative agent of infantile gastroenteritis, is mediated by interactions with specific cellular glycans. The distally located VP8* domain of the rotavirus spike protein VP4 (ref. 5) mediates such interactions. The existing paradigm is that 'sialidase-sensitive' animal rotavirus strains bind to glycans with terminal sialic acid (Sia), whereas 'sialidase-insensitive' human rotavirus strains bind to glycans with internal Sia such as GM1 (ref. 3). Although the involvement of Sia in the animal strains is firmly supported by crystallographic studies, it is not yet known how VP8* of human rotaviruses interacts with Sia and whether their cell attachment necessarily involves sialoglycans. Here we show that VP8* of a human rotavirus strain specifically recognizes A-type histo-blood group antigen (HBGA) using a glycan array screen comprised of 511 glycans, and that virus infectivity in HT-29 cells is abrogated by anti-A-type antibodies as well as significantly enhanced in Chinese hamster ovary cells genetically modified to express the A-type HBGA, providing a novel paradigm for initial cell attachment of human rotavirus. HBGAs are genetically determined glycoconjugates present in mucosal secretions, epithelia and on red blood cells, and are recognized as susceptibility and cell attachment factors for gastric pathogens like Helicobacter pylori and noroviruses. Our crystallographic studies show that the A-type HBGA binds to the human rotavirus VP8* at the same location as the Sia in the VP8* of animal rotavirus, and suggest how subtle changes within the same structural framework allow for such receptor switching. These results raise the possibility that host susceptibility to specific human rotavirus strains and pathogenesis are influenced by genetically controlled expression of different HBGAs among the world's population.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3350622/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3350622/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hu, Liya -- Crawford, Sue E -- Czako, Rita -- Cortes-Penfield, Nicolas W -- Smith, David F -- Le Pendu, Jacques -- Estes, Mary K -- Prasad, B V Venkataram -- AI 080656/AI/NIAID NIH HHS/ -- AI36040/AI/NIAID NIH HHS/ -- GM62116/GM/NIGMS NIH HHS/ -- P30 DK056338/DK/NIDDK NIH HHS/ -- P30 DK56338/DK/NIDDK NIH HHS/ -- P41 GM103694/GM/NIGMS NIH HHS/ -- R01 AI080656/AI/NIAID NIH HHS/ -- U54 GM062116/GM/NIGMS NIH HHS/ -- U54 GM062116-01A1/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Apr 15;485(7397):256-9. doi: 10.1038/nature10996.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22504179" target="_blank"〉PubMed〈/a〉
    Keywords: ABO Blood-Group System/chemistry/genetics/immunology/*metabolism ; Amino Acid Sequence ; Animals ; CHO Cells ; Cricetinae ; Crystallography, X-Ray ; Erythrocytes/metabolism/virology ; Host Specificity/*physiology ; Humans ; Models, Molecular ; Molecular Sequence Data ; N-Acetylneuraminic Acid/antagonists & inhibitors/chemistry/immunology/metabolism ; RNA-Binding Proteins/chemistry/*metabolism ; Receptors, Virus/chemistry/genetics/*metabolism ; *Rotavirus/chemistry/classification/metabolism/pathogenicity ; Viral Nonstructural Proteins/chemistry/*metabolism
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  • 97
    Publication Date: 2012-03-13
    Description: The hydrosulphide ion (HS(-)) and its undissociated form, hydrogen sulphide (H(2)S), which are believed to have been critical to the origin of life on Earth, remain important in physiology and cellular signalling. As a major metabolite in anaerobic bacterial growth, hydrogen sulphide is a product of both assimilatory and dissimilatory sulphate reduction. These pathways can reduce various oxidized sulphur compounds including sulphate, sulphite and thiosulphate. The dissimilatory sulphate reduction pathway uses this molecule as the terminal electron acceptor for anaerobic respiration, in which process it produces excess amounts of H(2)S (ref. 4). The reduction of sulphite is a key intermediate step in all sulphate reduction pathways. In Clostridium and Salmonella, an inducible sulphite reductase is directly linked to the regeneration of NAD(+), which has been suggested to have a role in energy production and growth, as well as in the detoxification of sulphite. Above a certain concentration threshold, both H(2)S and HS(-) inhibit cell growth by binding the metal centres of enzymes and cytochrome oxidase, necessitating a release mechanism for the export of this toxic metabolite from the cell. Here we report the identification of a hydrosulphide ion channel in the pathogen Clostridium difficile through a combination of genetic, biochemical and functional approaches. The HS(-) channel is a member of the formate/nitrite transport family, in which about 50 hydrosulphide ion channels form a third subfamily alongside those for formate (FocA) and for nitrite (NirC). The hydrosulphide ion channel is permeable to formate and nitrite as well as to HS(-) ions. Such polyspecificity can be explained by the conserved ion selectivity filter observed in the channel's crystal structure. The channel has a low open probability and is tightly regulated, to avoid decoupling of the membrane proton gradient.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3711795/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3711795/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Czyzewski, Bryan K -- Wang, Da-Neng -- F31 AI086072/AI/NIAID NIH HHS/ -- F31-AI086072/AI/NIAID NIH HHS/ -- R01 DK053973/DK/NIDDK NIH HHS/ -- R01 GM093825/GM/NIGMS NIH HHS/ -- R01 MH083840/MH/NIMH NIH HHS/ -- R01-DK053973-08A1S1/DK/NIDDK NIH HHS/ -- R01-DK073973/DK/NIDDK NIH HHS/ -- R01-GM093825/GM/NIGMS NIH HHS/ -- R01-MH083840/MH/NIMH NIH HHS/ -- U54 GM075026/GM/NIGMS NIH HHS/ -- U54-GM075026/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Mar 11;483(7390):494-7. doi: 10.1038/nature10881.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, New York 10016, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22407320" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/chemistry/genetics/isolation & purification/metabolism ; *Clostridium difficile/chemistry/drug effects/genetics ; Crystallography, X-Ray ; Formates/metabolism ; Ion Channel Gating ; Ion Channels/chemistry/genetics/*isolation & purification/*metabolism ; Ion Transport ; Models, Biological ; Models, Molecular ; Nitrites/metabolism ; Operon/genetics ; Proteolipids/metabolism ; Proton-Motive Force ; Structure-Activity Relationship ; Substrate Specificity ; Sulfides/*metabolism/toxicity
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  • 98
    Publication Date: 2012-06-09
    Description: In excitable cells, voltage-gated sodium (Na(V)) channels activate to initiate action potentials and then undergo fast and slow inactivation processes that terminate their ionic conductance. Inactivation is a hallmark of Na(V) channel function and is critical for control of membrane excitability, but the structural basis for this process has remained elusive. Here we report crystallographic snapshots of the wild-type Na(V)Ab channel from Arcobacter butzleri captured in two potentially inactivated states at 3.2 A resolution. Compared to previous structures of Na(V)Ab channels with cysteine mutations in the pore-lining S6 helices (ref. 4), the S6 helices and the intracellular activation gate have undergone significant rearrangements: one pair of S6 helices has collapsed towards the central pore axis and the other S6 pair has moved outward to produce a striking dimer-of-dimers configuration. An increase in global structural asymmetry is observed throughout our wild-type Na(V)Ab models, reshaping the ion selectivity filter at the extracellular end of the pore, the central cavity and its residues that are analogous to the mammalian drug receptor site, and the lateral pore fenestrations. The voltage-sensing domains have also shifted around the perimeter of the pore module in wild-type Na(V)Ab, compared to the mutant channel, and local structural changes identify a conserved interaction network that connects distant molecular determinants involved in Na(V) channel gating and inactivation. These potential inactivated-state structures provide new insights into Na(V) channel gating and novel avenues to drug development and therapy for a range of debilitating Na(V) channelopathies.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552482/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552482/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Payandeh, Jian -- Gamal El-Din, Tamer M -- Scheuer, Todd -- Zheng, Ning -- Catterall, William A -- R01 HL112808/HL/NHLBI NIH HHS/ -- R01 NS015751/NS/NINDS NIH HHS/ -- R01 NS15751/NS/NINDS NIH HHS/ -- U01 NS058039/NS/NINDS NIH HHS/ -- Canadian Institutes of Health Research/Canada -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 May 20;486(7401):135-9. doi: 10.1038/nature11077.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22678296" target="_blank"〉PubMed〈/a〉
    Keywords: Arcobacter/*chemistry ; Conserved Sequence ; Crystallization ; Crystallography, X-Ray ; *Ion Channel Gating ; Models, Molecular ; Protein Conformation ; Sodium Channels/*chemistry/metabolism ; Structure-Activity Relationship
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  • 99
    Publication Date: 2011-11-29
    Description: The anaerobic oxidation of methane (AOM) with sulphate, an area currently generating great interest in microbiology, is accomplished by consortia of methanotrophic archaea (ANME) and sulphate-reducing bacteria. The enzyme activating methane in methanotrophic archaea has tentatively been identified as a homologue of methyl-coenzyme M reductase (MCR) that catalyses the methane-forming step in methanogenic archaea. Here we report an X-ray structure of the 280 kDa heterohexameric ANME-1 MCR complex. It was crystallized uniquely from a protein ensemble purified from consortia of microorganisms collected with a submersible from a Black Sea mat catalysing AOM with sulphate. Crystals grown from the heterogeneous sample diffract to 2.1 A resolution and consist of a single ANME-1 MCR population, demonstrating the strong selective power of crystallization. The structure revealed ANME-1 MCR in complex with coenzyme M and coenzyme B, indicating the same substrates for MCR from methanotrophic and methanogenic archaea. Differences between the highly similar structures of ANME-1 MCR and methanogenic MCR include a F(430) modification, a cysteine-rich patch and an altered post-translational amino acid modification pattern, which may tune the enzymes for their functions in different biological contexts.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shima, Seigo -- Krueger, Martin -- Weinert, Tobias -- Demmer, Ulrike -- Kahnt, Jorg -- Thauer, Rudolf K -- Ermler, Ulrich -- England -- Nature. 2011 Nov 27;481(7379):98-101. doi: 10.1038/nature10663.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Institute for Terrestrial Microbiology, Karl-Frisch-Strasse 10, D-35043 Marburg, Germany. shima@mpi-marburg.mpg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22121022" target="_blank"〉PubMed〈/a〉
    Keywords: Anaerobiosis ; Archaea/*enzymology/isolation & purification/metabolism ; *Biocatalysis ; Black Sea ; Catalytic Domain ; Coenzymes/chemistry/metabolism ; Crystallography, X-Ray ; Cysteine/metabolism ; Expeditions ; Methane/*metabolism ; Models, Molecular ; Oxidation-Reduction ; Oxidoreductases/*chemistry/*metabolism ; Protein Conformation ; Seawater/*microbiology ; Ships ; Sulfates/metabolism
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  • 100
    Publication Date: 2012-03-13
    Description: Food-borne hemorrhagic Escherichia coli, exemplified by the strains O157:H7 and O104:H4 (refs 1, 2), require elaborate acid-resistance systems (ARs) to survive the extremely acidic environment such as the stomach (pH approximately 2). AR2 expels intracellular protons through the decarboxylation of L-glutamate (Glu) in the cytoplasm and exchange of the reaction product gamma-aminobutyric acid (GABA) with extracellular Glu. The latter process is mediated by the Glu-GABA antiporter GadC, a representative member of the amino-acid-polyamine-organocation superfamily of membrane transporters. The functional mechanism of GadC remains largely unknown. Here we show, with the use of an in vitro proteoliposome-based assay, that GadC transports GABA/Glu only under acidic conditions, with no detectable activity at pH values higher than 6.5. We determined the crystal structure of E. coli GadC at 3.1 A resolution under basic conditions. GadC, comprising 12 transmembrane segments (TMs), exists in a closed state, with its carboxy-terminal domain serving as a plug to block an otherwise inward-open conformation. Structural and biochemical analyses reveal the essential transport residues, identify the transport path and suggest a conserved transport mechanism involving the rigid-body rotation of a helical bundle for GadC and other amino acid antiporters.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ma, Dan -- Lu, Peilong -- Yan, Chuangye -- Fan, Chao -- Yin, Ping -- Wang, Jiawei -- Shi, Yigong -- England -- Nature. 2012 Mar 11;483(7391):632-6. doi: 10.1038/nature10917.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22407317" target="_blank"〉PubMed〈/a〉
    Keywords: Antiporters/*chemistry/*metabolism ; Biological Transport ; Crystallography, X-Ray ; Escherichia coli O157/*chemistry ; Escherichia coli Proteins/*chemistry/*metabolism ; Glutamic Acid/*metabolism ; Membrane Proteins/*chemistry/*metabolism ; Models, Molecular ; Protein Structure, Tertiary ; Proteolipids/metabolism ; Rotation ; Structure-Activity Relationship ; gamma-Aminobutyric Acid/*metabolism
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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