ALBERT

Description: Eukaryotic cells restrict protein synthesis under various stress conditions, by inhibiting the eukaryotic translation initiation factor 2B (eIF2B). eIF2B is the guanine nucleotide exchange factor for eIF2, a heterotrimeric G protein consisting of alpha-, beta- and gamma-subunits. eIF2B exchanges GDP for GTP on the gamma-subunit of eIF2 (eIF2gamma), and is inhibited by stress-induced phosphorylation of eIF2alpha. eIF2B is a heterodecameric complex of two copies each of the alpha-, beta-, gamma-, delta- and epsilon-subunits; its alpha-, beta- and delta-subunits constitute the regulatory subcomplex, while the gamma- and epsilon-subunits form the catalytic subcomplex. The three-dimensional structure of the entire eIF2B complex has not been determined. Here we present the crystal structure of Schizosaccharomyces pombe eIF2B with an unprecedented subunit arrangement, in which the alpha2beta2delta2 hexameric regulatory subcomplex binds two gammaepsilon dimeric catalytic subcomplexes on its opposite sides. A structure-based in vitro analysis by a surface-scanning site-directed photo-cross-linking method identified the eIF2alpha-binding and eIF2gamma-binding interfaces, located far apart on the regulatory and catalytic subcomplexes, respectively. The eIF2gamma-binding interface is located close to the conserved 'NF motif', which is important for nucleotide exchange. A structural model was constructed for the complex of eIF2B with phosphorylated eIF2alpha, which binds to eIF2B more strongly than the unphosphorylated form. These results indicate that the eIF2alpha phosphorylation generates the 'nonproductive' eIF2-eIF2B complex, which prevents nucleotide exchange on eIF2gamma, and thus provide a structural framework for the eIF2B-mediated mechanism of stress-induced translational control.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kashiwagi, Kazuhiro -- Takahashi, Mari -- Nishimoto, Madoka -- Hiyama, Takuya B -- Higo, Toshiaki -- Umehara, Takashi -- Sakamoto, Kensaku -- Ito, Takuhiro -- Yokoyama, Shigeyuki -- England -- Nature. 2016 Mar 3;531(7592):122-5. doi: 10.1038/nature16991. Epub 2016 Feb 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan. ; RIKEN Systems and Structural Biology Center, Tsurumi-ku, Yokohama 230-0045, Japan. ; RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan. ; RIKEN Structural Biology Laboratory, Tsurumi-ku, Yokohama 230-0045, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26901872" target="_blank"〉PubMed〈/a〉

Description: Catalysis in biology is restricted to RNA (ribozymes) and protein enzymes, but synthetic biomolecular catalysts can also be made of DNA (deoxyribozymes) or synthetic genetic polymers. In vitro selection from synthetic random DNA libraries identified DNA catalysts for various chemical reactions beyond RNA backbone cleavage. DNA-catalysed reactions include RNA and DNA ligation in various topologies, hydrolytic cleavage and photorepair of DNA, as well as reactions of peptides and small molecules. In spite of comprehensive biochemical studies of DNA catalysts for two decades, fundamental mechanistic understanding of their function is lacking in the absence of three-dimensional models at atomic resolution. Early attempts to solve the crystal structure of an RNA-cleaving deoxyribozyme resulted in a catalytically irrelevant nucleic acid fold. Here we report the crystal structure of the RNA-ligating deoxyribozyme 9DB1 (ref. 14) at 2.8 A resolution. The structure captures the ligation reaction in the post-catalytic state, revealing a compact folding unit stabilized by numerous tertiary interactions, and an unanticipated organization of the catalytic centre. Structure-guided mutagenesis provided insights into the basis for regioselectivity of the ligation reaction and allowed remarkable manipulation of substrate recognition and reaction rate. Moreover, the structure highlights how the specific properties of deoxyribose are reflected in the backbone conformation of the DNA catalyst, in support of its intricate three-dimensional organization. The structural principles underlying the catalytic ability of DNA elucidate differences and similarities in DNA versus RNA catalysts, which is relevant for comprehending the privileged position of folded RNA in the prebiotic world and in current organisms.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ponce-Salvatierra, Almudena -- Wawrzyniak-Turek, Katarzyna -- Steuerwald, Ulrich -- Hobartner, Claudia -- Pena, Vladimir -- England -- Nature. 2016 Jan 14;529(7585):231-4. doi: 10.1038/nature16471. Epub 2016 Jan 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Gottingen, Germany. ; Research Group Macromolecular Crystallography, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Gottingen, Germany. ; Institute for Organic and Biomolecular Chemistry, Georg-August-University Gottingen, Tammannstr. 2, 37077 Gottingen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26735012" target="_blank"〉PubMed〈/a〉

Description: All Gram-negative bacteria, mitochondria and chloroplasts have outer membrane proteins (OMPs) that perform many fundamental biological processes. The OMPs in Gram-negative bacteria are inserted and folded into the outer membrane by the beta-barrel assembly machinery (BAM). The mechanism involved is poorly understood, owing to the absence of a structure of the entire BAM complex. Here we report two crystal structures of the Escherichia coli BAM complex in two distinct states: an inward-open state and a lateral-open state. Our structures reveal that the five polypeptide transport-associated domains of BamA form a ring architecture with four associated lipoproteins, BamB-BamE, in the periplasm. Our structural, functional studies and molecular dynamics simulations indicate that these subunits rotate with respect to the integral membrane beta-barrel of BamA to induce movement of the beta-strands of the barrel and promote insertion of the nascent OMP.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gu, Yinghong -- Li, Huanyu -- Dong, Haohao -- Zeng, Yi -- Zhang, Zhengyu -- Paterson, Neil G -- Stansfeld, Phillip J -- Wang, Zhongshan -- Zhang, Yizheng -- Wang, Wenjian -- Dong, Changjiang -- G1100110/1/Medical Research Council/United Kingdom -- WT106121MA/Wellcome Trust/United Kingdom -- England -- Nature. 2016 Mar 3;531(7592):64-9. doi: 10.1038/nature17199. Epub 2016 Feb 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK. ; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK. ; Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK. ; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou 221004, China. ; Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Sciences, Sichuan University, Chengdu 610064, China. ; Laboratory of Department of Surgery, the First Affiliated Hospital, Sun Yat-sen University, 58 Zhongshan Road II, Guangzhou, Guangdong 510080, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26901871" target="_blank"〉PubMed〈/a〉

Description: Many biopolymers, including polysaccharides, must be translocated across at least one membrane to reach their site of biological function. Cellulose is a linear glucose polymer synthesized and secreted by a membrane-integrated cellulose synthase. Here, in crystallo enzymology with the catalytically active bacterial cellulose synthase BcsA-BcsB complex reveals structural snapshots of a complete cellulose biosynthesis cycle, from substrate binding to polymer translocation. Substrate- and product-bound structures of BcsA provide the basis for substrate recognition and demonstrate the stepwise elongation of cellulose. Furthermore, the structural snapshots show that BcsA translocates cellulose via a ratcheting mechanism involving a 'finger helix' that contacts the polymer's terminal glucose. Cooperating with BcsA's gating loop, the finger helix moves 'up' and 'down' in response to substrate binding and polymer elongation, respectively, thereby pushing the elongated polymer into BcsA's transmembrane channel. This mechanism is validated experimentally by tethering BcsA's finger helix, which inhibits polymer translocation but not elongation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4843519/" 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/PMC4843519/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Morgan, Jacob L W -- McNamara, Joshua T -- Fischer, Michael -- Rich, Jamie -- Chen, Hong-Ming -- Withers, Stephen G -- Zimmer, Jochen -- 1R01GM101001/GM/NIGMS NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- R01 GM101001/GM/NIGMS NIH HHS/ -- S10 RR029205/RR/NCRR NIH HHS/ -- England -- Nature. 2016 Mar 17;531(7594):329-34. doi: 10.1038/nature16966. Epub 2016 Mar 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Virginia School of Medicine, Center for Membrane Biology, Molecular Physiology and Biological Physics, 480 Ray C. Hunt Drive, Charlottesville, Virginia 22908, USA. ; Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26958837" target="_blank"〉PubMed〈/a〉

Description: Nonribosomal peptide synthetases (NRPSs) are very large proteins that produce small peptide molecules with wide-ranging biological activities, including environmentally friendly chemicals and many widely used therapeutics. NRPSs are macromolecular machines, with modular assembly-line logic, a complex catalytic cycle, moving parts and many active sites. In addition to the core domains required to link the substrates, they often include specialized tailoring domains, which introduce chemical modifications and allow the product to access a large expanse of chemical space. It is still unknown how the NRPS tailoring domains are structurally accommodated into megaenzymes or how they have adapted to function in nonribosomal peptide synthesis. Here we present a series of crystal structures of the initiation module of an antibiotic-producing NRPS, linear gramicidin synthetase. This module includes the specialized tailoring formylation domain, and states are captured that represent every major step of the assembly-line synthesis in the initiation module. The transitions between conformations are large in scale, with both the peptidyl carrier protein domain and the adenylation subdomain undergoing huge movements to transport substrate between distal active sites. The structures highlight the great versatility of NRPSs, as small domains repurpose and recycle their limited interfaces to interact with their various binding partners. Understanding tailoring domains is important if NRPSs are to be utilized in the production of novel therapeutics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reimer, Janice M -- Aloise, Martin N -- Harrison, Paul M -- Schmeing, T Martin -- 106615/Canadian Institutes of Health Research/Canada -- England -- Nature. 2016 Jan 14;529(7585):239-42. doi: 10.1038/nature16503.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, McGill University, 3649 Promenade Sir-William-Osler, Montreal, Quebec H3G 0B1, Canada. ; Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, Quebec H3A 1B1, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26762462" target="_blank"〉PubMed〈/a〉

Description: Ubiquitination is a central process affecting all facets of cellular signalling and function. A critical step in ubiquitination is the transfer of ubiquitin from an E2 ubiquitin-conjugating enzyme to a substrate or a growing ubiquitin chain, which is mediated by E3 ubiquitin ligases. RING-type E3 ligases typically facilitate the transfer of ubiquitin from the E2 directly to the substrate. The RING-between-RING (RBR) family of RING-type E3 ligases, however, breaks this paradigm by forming a covalent intermediate with ubiquitin similarly to HECT-type E3 ligases. The RBR family includes Parkin and HOIP, the central catalytic factor of the LUBAC (linear ubiquitin chain assembly complex). While structural insights into the RBR E3 ligases Parkin and HHARI in their overall auto-inhibited forms are available, no structures exist of intact fully active RBR E3 ligases or any of their complexes. Thus, the RBR mechanism of action has remained largely unknown. Here we present the first structure, to our knowledge, of the fully active human HOIP RBR in its transfer complex with an E2~ubiquitin conjugate, which elucidates the intricate nature of RBR E3 ligases. The active HOIP RBR adopts a conformation markedly different from that of auto-inhibited RBRs. HOIP RBR binds the E2~ubiquitin conjugate in an elongated fashion, with the E2 and E3 catalytic centres ideally aligned for ubiquitin transfer, which structurally both requires and enables a HECT-like mechanism. In addition, three distinct helix-IBR-fold motifs inherent to RBRs form ubiquitin-binding regions that engage the activated ubiquitin of the E2~ubiquitin conjugate and, surprisingly, an additional regulatory ubiquitin molecule. The features uncovered reveal critical states of the HOIP RBR E3 ligase cycle, and comparison with Parkin and HHARI suggests a general mechanism for RBR E3 ligases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lechtenberg, Bernhard C -- Rajput, Akhil -- Sanishvili, Ruslan -- Dobaczewska, Malgorzata K -- Ware, Carl F -- Mace, Peter D -- Riedl, Stefan J -- P30 CA030199/CA/NCI NIH HHS/ -- P30CA030199/CA/NCI NIH HHS/ -- R01AA017238/AA/NIAAA NIH HHS/ -- England -- Nature. 2016 Jan 28;529(7587):546-50. doi: 10.1038/nature16511. Epub 2016 Jan 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA. ; Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA. ; X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA. ; Biochemistry Department, University of Otago, 710 Cumberland Street, Dunedin 9054, New Zealand.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26789245" target="_blank"〉PubMed〈/a〉

Description: (beta-)Arrestins are important regulators of G-protein-coupled receptors (GPCRs). They bind to active, phosphorylated GPCRs and thereby shut off 'classical' signalling to G proteins, trigger internalization of GPCRs via interaction with the clathrin machinery and mediate signalling via 'non-classical' pathways. In addition to two visual arrestins that bind to rod and cone photoreceptors (termed arrestin1 and arrestin4), there are only two (non-visual) beta-arrestin proteins (beta-arrestin1 and beta-arrestin2, also termed arrestin2 and arrestin3), which regulate hundreds of different (non-visual) GPCRs. Binding of these proteins to GPCRs usually requires the active form of the receptors plus their phosphorylation by G-protein-coupled receptor kinases (GRKs). The binding of receptors or their carboxy terminus as well as certain truncations induce active conformations of (beta-)arrestins that have recently been solved by X-ray crystallography. Here we investigate both the interaction of beta-arrestin with GPCRs, and the beta-arrestin conformational changes in real time and in living human cells, using a series of fluorescence resonance energy transfer (FRET)-based beta-arrestin2 biosensors. We observe receptor-specific patterns of conformational changes in beta-arrestin2 that occur rapidly after the receptor-beta-arrestin2 interaction. After agonist removal, these changes persist for longer than the direct receptor interaction. Our data indicate a rapid, receptor-type-specific, two-step binding and activation process between GPCRs and beta-arrestins. They further indicate that beta-arrestins remain active after dissociation from receptors, allowing them to remain at the cell surface and presumably signal independently. Thus, GPCRs trigger a rapid, receptor-specific activation/deactivation cycle of beta-arrestins, which permits their active signalling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nuber, Susanne -- Zabel, Ulrike -- Lorenz, Kristina -- Nuber, Andreas -- Milligan, Graeme -- Tobin, Andrew B -- Lohse, Martin J -- Hoffmann, Carsten -- 1 R01 DA038882/DA/NIDA NIH HHS/ -- BB/K019864/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2016 Mar 31;531(7596):661-4. doi: 10.1038/nature17198. Epub 2016 Mar 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Pharmacology and Toxicology, University of Wurzburg, Versbacher Str. 9, 97078 Wurzburg, Germany. ; Rudolf Virchow Center, University of Wurzburg, Versbacher Str. 9, 97078 Wurzburg, Germany. ; Comprehensive Heart Failure Center, University of Wurzburg, Versbacher Str. 9, 97078 Wurzburg, Germany. ; Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. ; MRC Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester LE1 9HN, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27007855" target="_blank"〉PubMed〈/a〉

Description: Many important natural products are produced by multidomain non-ribosomal peptide synthetases (NRPSs). During synthesis, intermediates are covalently bound to integrated carrier domains and transported to neighbouring catalytic domains in an assembly line fashion. Understanding the structural basis for catalysis with non-ribosomal peptide synthetases will facilitate bioengineering to create novel products. Here we describe the structures of two different holo-non-ribosomal peptide synthetase modules, each revealing a distinct step in the catalytic cycle. One structure depicts the carrier domain cofactor bound to the peptide bond-forming condensation domain, whereas a second structure captures the installation of the amino acid onto the cofactor within the adenylation domain. These structures demonstrate that a conformational change within the adenylation domain guides transfer of intermediates between domains. Furthermore, one structure shows that the condensation and adenylation domains simultaneously adopt their catalytic conformations, increasing the overall efficiency in a revised structural cycle. These structures and the single-particle electron microscopy analysis demonstrate a highly dynamic domain architecture and provide the foundation for understanding the structural mechanisms that could enable engineering of novel non-ribosomal peptide synthetases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Drake, Eric J -- Miller, Bradley R -- Shi, Ce -- Tarrasch, Jeffrey T -- Sundlov, Jesse A -- Allen, C Leigh -- Skiniotis, Georgios -- Aldrich, Courtney C -- Gulick, Andrew M -- GM-068440/GM/NIGMS NIH HHS/ -- GM-115601/GM/NIGMS NIH HHS/ -- R01 GM068440/GM/NIGMS NIH HHS/ -- England -- Nature. 2016 Jan 14;529(7585):235-8. doi: 10.1038/nature16163.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, New York 14203, USA. ; Department of Structural Biology, University at Buffalo, Buffalo, New York 14203, USA. ; Center for Drug Design and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. ; Life Sciences Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26762461" target="_blank"〉PubMed〈/a〉

Description: The CRISPR-Cas systems, as exemplified by CRISPR-Cas9, are RNA-guided adaptive immune systems used by bacteria and archaea to defend against viral infection. The CRISPR-Cpf1 system, a new class 2 CRISPR-Cas system, mediates robust DNA interference in human cells. Although functionally conserved, Cpf1 and Cas9 differ in many aspects including their guide RNAs and substrate specificity. Here we report the 2.38 A crystal structure of the CRISPR RNA (crRNA)-bound Lachnospiraceae bacterium ND2006 Cpf1 (LbCpf1). LbCpf1 has a triangle-shaped architecture with a large positively charged channel at the centre. Recognized by the oligonucleotide-binding domain of LbCpf1, the crRNA adopts a highly distorted conformation stabilized by extensive intramolecular interactions and the (Mg(H2O)6)(2+) ion. The oligonucleotide-binding domain also harbours a looped-out helical domain that is important for LbCpf1 substrate binding. Binding of crRNA or crRNA lacking the guide sequence induces marked conformational changes but no oligomerization of LbCpf1. Our study reveals the crRNA recognition mechanism and provides insight into crRNA-guided substrate binding of LbCpf1, establishing a framework for engineering LbCpf1 to improve its efficiency and specificity for genome editing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dong, De -- Ren, Kuan -- Qiu, Xiaolin -- Zheng, Jianlin -- Guo, Minghui -- Guan, Xiaoyu -- Liu, Hongnan -- Li, Ningning -- Zhang, Bailing -- Yang, Daijun -- Ma, Chuang -- Wang, Shuo -- Wu, Dan -- Ma, Yunfeng -- Fan, Shilong -- Wang, Jiawei -- Gao, Ning -- Huang, Zhiwei -- England -- Nature. 2016 Apr 28;532(7600):522-6. doi: 10.1038/nature17944. Epub 2016 Apr 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Life Science and Technology, Harbin Institute of Technology, Harbin 150080, China. ; Ministry of Education Key Laboratory of Protein Sciences, 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/27096363" target="_blank"〉PubMed〈/a〉

Description: The human sigma1 receptor is an enigmatic endoplasmic-reticulum-resident transmembrane protein implicated in a variety of disorders including depression, drug addiction, and neuropathic pain. Recently, an additional connection to amyotrophic lateral sclerosis has emerged from studies of human genetics and mouse models. Unlike many transmembrane receptors that belong to large, extensively studied families such as G-protein-coupled receptors or ligand-gated ion channels, the sigma1 receptor is an evolutionary isolate with no discernible similarity to any other human protein. Despite its increasingly clear importance in human physiology and disease, the molecular architecture of the sigma1 receptor and its regulation by drug-like compounds remain poorly defined. Here we report crystal structures of the human sigma1 receptor in complex with two chemically divergent ligands, PD144418 and 4-IBP. The structures reveal a trimeric architecture with a single transmembrane domain in each protomer. The carboxy-terminal domain of the receptor shows an extensive flat, hydrophobic membrane-proximal surface, suggesting an intimate association with the cytosolic surface of the endoplasmic reticulum membrane in cells. This domain includes a cupin-like beta-barrel with the ligand-binding site buried at its centre. This large, hydrophobic ligand-binding cavity shows remarkable plasticity in ligand recognition, binding the two ligands in similar positions despite dissimilar chemical structures. Taken together, these results reveal the overall architecture, oligomerization state, and molecular basis for ligand recognition by this important but poorly understood protein.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schmidt, Hayden R -- Zheng, Sanduo -- Gurpinar, Esin -- Koehl, Antoine -- Manglik, Aashish -- Kruse, Andrew C -- T32GM007226/GM/NIGMS NIH HHS/ -- England -- Nature. 2016 Apr 28;532(7600):527-30. doi: 10.1038/nature17391. Epub 2016 Apr 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA. ; 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/27042935" target="_blank"〉PubMed〈/a〉

Description: Hydrophobic signal sequences target secretory polypeptides to a protein-conducting channel formed by a heterotrimeric membrane protein complex, the prokaryotic SecY or eukaryotic Sec61 complex. How signal sequences are recognized is poorly understood, particularly because they are diverse in sequence and length. Structures of the inactive channel show that the largest subunit, SecY or Sec61alpha, consists of two halves that form an hourglass-shaped pore with a constriction in the middle of the membrane and a lateral gate that faces lipid. The cytoplasmic funnel is empty, while the extracellular funnel is filled with a plug domain. In bacteria, the SecY channel associates with the translating ribosome in co-translational translocation, and with the SecA ATPase in post-translational translocation. How a translocating polypeptide inserts into the channel is uncertain, as cryo-electron microscopy structures of the active channel have a relatively low resolution (~10 A) or are of insufficient quality. Here we report a crystal structure of the active channel, assembled from SecY complex, the SecA ATPase, and a segment of a secretory protein fused into SecA. The translocating protein segment inserts into the channel as a loop, displacing the plug domain. The hydrophobic core of the signal sequence forms a helix that sits in a groove outside the lateral gate, while the following polypeptide segment intercalates into the gate. The carboxy (C)-terminal section of the polypeptide loop is located in the channel, surrounded by residues of the pore ring. Thus, during translocation, the hydrophobic segments of signal sequences, and probably bilayer-spanning domains of nascent membrane proteins, exit the lateral gate and dock at a specific site that faces the lipid phase.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4855518/" 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/PMC4855518/" 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 -- Park, Eunyong -- Ling, JingJing -- Ingram, Jessica -- Ploegh, Hidde -- Rapoport, Tom A -- GM052586/GM/NIGMS NIH HHS/ -- R01 GM052586/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2016 Mar 17;531(7594):395-9. doi: 10.1038/nature17163. Epub 2016 Mar 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Harvard Medical School, Department of Cell Biology, 240 Longwood Avenue, Boston, Massachusetts 02115, USA. ; Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26950603" target="_blank"〉PubMed〈/a〉

Description: Retroviral integrase catalyses the integration of viral DNA into host target DNA, which is an essential step in the life cycle of all retroviruses. Previous structural characterization of integrase-viral DNA complexes, or intasomes, from the spumavirus prototype foamy virus revealed a functional integrase tetramer, and it is generally believed that intasomes derived from other retroviral genera use tetrameric integrase. However, the intasomes of orthoretroviruses, which include all known pathogenic species, have not been characterized structurally. Here, using single-particle cryo-electron microscopy and X-ray crystallography, we determine an unexpected octameric integrase architecture for the intasome of the betaretrovirus mouse mammary tumour virus. The structure is composed of two core integrase dimers, which interact with the viral DNA ends and structurally mimic the integrase tetramer of prototype foamy virus, and two flanking integrase dimers that engage the core structure via their integrase carboxy-terminal domains. Contrary to the belief that tetrameric integrase components are sufficient to catalyse integration, the flanking integrase dimers were necessary for mouse mammary tumour virus integrase activity. The integrase octamer solves a conundrum for betaretroviruses as well as alpharetroviruses by providing critical carboxy-terminal domains to the intasome core that cannot be provided in cis because of evolutionarily restrictive catalytic core domain-carboxy-terminal domain linker regions. The octameric architecture of the intasome of mouse mammary tumour virus provides new insight into the structural basis of retroviral DNA integration.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ballandras-Colas, Allison -- Brown, Monica -- Cook, Nicola J -- Dewdney, Tamaria G -- Demeler, Borries -- Cherepanov, Peter -- Lyumkis, Dmitry -- Engelman, Alan N -- 9 P41 GM103310/GM/NIGMS NIH HHS/ -- P30 AI060354/AI/NIAID NIH HHS/ -- P41 GM103331/GM/NIGMS NIH HHS/ -- P50 GM082251/GM/NIGMS NIH HHS/ -- P50 GM103368/GM/NIGMS NIH HHS/ -- R01 AI070042/AI/NIAID NIH HHS/ -- England -- Nature. 2016 Feb 18;530(7590):358-61. doi: 10.1038/nature16955.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, 450 Brookline Avenue, Boston, Massachusetts 02215, USA. ; Laboratory of Genetics and Helmsley Center for Genomic Medicine, The Salk Institute for Biological Studies, 10010 N Torrey Pines Road, La Jolla, California 92037, USA. ; Clare Hall Laboratories, The Francis Crick Institute, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3LD, UK. ; Department of Biochemistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA. ; Division of Medicine, Imperial College London, St. Mary's Campus, Norfolk Place, London W2 1PG, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26887496" target="_blank"〉PubMed〈/a〉

Description: G protein-coupled receptors (GPCRs) are physiologically important transmembrane signalling proteins that trigger intracellular responses upon binding of extracellular ligands. Despite recent breakthroughs in GPCR crystallography, the details of ligand-induced signal transduction are not well understood owing to missing dynamical information. In principle, such information can be provided by NMR, but so far only limited data of functional relevance on few side-chain sites of eukaryotic GPCRs have been obtained. Here we show that receptor motions can be followed at virtually any backbone site in a thermostabilized mutant of the turkey beta1-adrenergic receptor (beta1AR). Labelling with [(15)N]valine in a eukaryotic expression system provides over twenty resolved resonances that report on structure and dynamics in six ligand complexes and the apo form. The response to the various ligands is heterogeneous in the vicinity of the binding pocket, but gets transformed into a homogeneous readout at the intracellular side of helix 5 (TM5), which correlates linearly with ligand efficacy for the G protein pathway. The effect of several pertinent, thermostabilizing point mutations was assessed by reverting them to the native sequence. Whereas the response to ligands remains largely unchanged, binding of the G protein mimetic nanobody NB80 and G protein activation are only observed when two conserved tyrosines (Y227 and Y343) are restored. Binding of NB80 leads to very strong spectral changes throughout the receptor, including the extracellular ligand entrance pocket. This indicates that even the fully thermostabilized receptor undergoes activating motions in TM5, but that the fully active state is only reached in presence of Y227 and Y343 by stabilization with a G protein-like partner. The combined analysis of chemical shift changes from the point mutations and ligand responses identifies crucial connections in the allosteric activation pathway, and presents a general experimental method to delineate signal transmission networks at high resolution in GPCRs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Isogai, Shin -- Deupi, Xavier -- Opitz, Christian -- Heydenreich, Franziska M -- Tsai, Ching-Ju -- Brueckner, Florian -- Schertler, Gebhard F X -- Veprintsev, Dmitry B -- Grzesiek, Stephan -- England -- Nature. 2016 Feb 11;530(7589):237-41. doi: 10.1038/nature16577. Epub 2016 Feb 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, CH-4056 Basel, Switzerland. ; Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland. ; Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26840483" target="_blank"〉PubMed〈/a〉

Description: The cullin-RING ubiquitin E3 ligase (CRL) family comprises over 200 members in humans. The COP9 signalosome complex (CSN) regulates CRLs by removing their ubiquitin-like activator NEDD8. The CUL4A-RBX1-DDB1-DDB2 complex (CRL4A(DDB2)) monitors the genome for ultraviolet-light-induced DNA damage. CRL4A(DBB2) is inactive in the absence of damaged DNA and requires CSN to regulate the repair process. The structural basis of CSN binding to CRL4A(DDB2) and the principles of CSN activation are poorly understood. Here we present cryo-electron microscopy structures for CSN in complex with neddylated CRL4A ligases to 6.4 A resolution. The CSN conformers defined by cryo-electron microscopy and a novel apo-CSN crystal structure indicate an induced-fit mechanism that drives CSN activation by neddylated CRLs. We find that CSN and a substrate cannot bind simultaneously to CRL4A, favouring a deneddylated, inactive state for substrate-free CRL4 complexes. These architectural and regulatory principles appear conserved across CRL families, allowing global regulation by CSN.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cavadini, Simone -- Fischer, Eric S -- Bunker, Richard D -- Potenza, Alessandro -- Lingaraju, Gondichatnahalli M -- Goldie, Kenneth N -- Mohamed, Weaam I -- Faty, Mahamadou -- Petzold, Georg -- Beckwith, Rohan E J -- Tichkule, Ritesh B -- Hassiepen, Ulrich -- Abdulrahman, Wassim -- Pantelic, Radosav S -- Matsumoto, Syota -- Sugasawa, Kaoru -- Stahlberg, Henning -- Thoma, Nicolas H -- England -- Nature. 2016 Mar 31;531(7596):598-603. doi: 10.1038/nature17416.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland. ; University of Basel, Petersplatz 10, 4003 Basel, Switzerland. ; Department of Cancer Biology, Dana-Farber Cancer Institute, LC-4312, 360 Longwood Avenue, Boston, Massachusetts 02215, USA. ; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02215, USA. ; Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, 4058 Basel, Switzerland. ; Novartis Institutes for Biomedical Research, 250 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Novartis Pharma AG, Institutes for Biomedical Research, Novartis Campus, 4056 Basel, Switzerland. ; Gatan R&D, 5974 W. Las Positas Boulevard, Pleasanton, California 94588, USA. ; Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, Kobe 657-8501, Japan. ; Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27029275" target="_blank"〉PubMed〈/a〉

Description: Thalidomide and its derivatives, lenalidomide and pomalidomide, are immune modulatory drugs (IMiDs) used in the treatment of haematologic malignancies. IMiDs bind CRBN, the substrate receptor of the CUL4-RBX1-DDB1-CRBN (also known as CRL4(CRBN)) E3 ubiquitin ligase, and inhibit ubiquitination of endogenous CRL4(CRBN) substrates. Unexpectedly, IMiDs also repurpose the ligase to target new proteins for degradation. Lenalidomide induces degradation of the lymphoid transcription factors Ikaros and Aiolos (also known as IKZF1 and IKZF3), and casein kinase 1alpha (CK1alpha), which contributes to its clinical efficacy in the treatment of multiple myeloma and 5q-deletion associated myelodysplastic syndrome (del(5q) MDS), respectively. How lenalidomide alters the specificity of the ligase to degrade these proteins remains elusive. Here we present the 2.45 A crystal structure of DDB1-CRBN bound to lenalidomide and CK1alpha. CRBN and lenalidomide jointly provide the binding interface for a CK1alpha beta-hairpin-loop located in the kinase N-lobe. We show that CK1alpha binding to CRL4(CRBN) is strictly dependent on the presence of an IMiD. Binding of IKZF1 to CRBN similarly requires the compound and both, IKZF1 and CK1alpha, use a related binding mode. Our study provides a mechanistic explanation for the selective efficacy of lenalidomide in del(5q) MDS therapy. We anticipate that high-affinity protein-protein interactions induced by small molecules will provide opportunities for drug development, particularly for targeted protein degradation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Petzold, Georg -- Fischer, Eric S -- Thoma, Nicolas H -- England -- Nature. 2016 Apr 7;532(7597):127-30. doi: 10.1038/nature16979. Epub 2016 Feb 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland. ; University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26909574" target="_blank"〉PubMed〈/a〉

Description: The p53 pro-apoptotic tumour suppressor is mutated or functionally altered in most cancers. In epithelial tumours induced by 'high-risk' mucosal human papilloma viruses, including human cervical carcinoma and a growing number of head-and-neck cancers, p53 is degraded by the viral oncoprotein E6 (ref. 2). In this process, E6 binds to a short leucine (L)-rich LxxLL consensus sequence within the cellular ubiquitin ligase E6AP. Subsequently, the E6/E6AP heterodimer recruits and degrades p53 (ref. 4). Neither E6 nor E6AP are separately able to recruit p53 (refs 3, 5), and the precise mode of assembly of E6, E6AP and p53 is unknown. Here we solve the crystal structure of a ternary complex comprising full-length human papilloma virus type 16 (HPV-16) E6, the LxxLL motif of E6AP and the core domain of p53. The LxxLL motif of E6AP renders the conformation of E6 competent for interaction with p53 by structuring a p53-binding cleft on E6. Mutagenesis of critical positions at the E6-p53 interface disrupts p53 degradation. The E6-binding site of p53 is distal from previously described DNA- and protein-binding surfaces of the core domain. This suggests that, in principle, E6 may avoid competition with cellular factors by targeting both free and bound p53 molecules. The E6/E6AP/p53 complex represents a prototype of viral hijacking of both the ubiquitin-mediated protein degradation pathway and the p53 tumour suppressor pathway. The present structure provides a framework for the design of inhibitory therapeutic strategies against oncogenesis mediated by human papilloma virus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martinez-Zapien, Denise -- Ruiz, Francesc Xavier -- Poirson, Juline -- Mitschler, Andre -- Ramirez, Juan -- Forster, Anne -- Cousido-Siah, Alexandra -- Masson, Murielle -- Vande Pol, Scott -- Podjarny, Alberto -- Trave, Gilles -- Zanier, Katia -- R01CA134737/CA/NCI NIH HHS/ -- England -- Nature. 2016 Jan 28;529(7587):541-5. doi: 10.1038/nature16481. Epub 2016 Jan 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Equipe labellisee Ligue, Biotechnologie et signalisation cellulaire UMR 7242, Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sebastien Brant, BP 10413, F-67412 Illkirch, France. ; Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC)/INSERM U964/CNRS UMR 7104/Universite de Strasbourg, 1 rue Laurent Fries, BP 10142, F-67404 Illkirch, France. ; Department of Pathology, University of Virginia, PO Box 800904, Charlottesville, Virginia 22908-0904, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26789255" target="_blank"〉PubMed〈/a〉

Description: Muscarinic M1-M5 acetylcholine receptors are G-protein-coupled receptors that regulate many vital functions of the central and peripheral nervous systems. In particular, the M1 and M4 receptor subtypes have emerged as attractive drug targets for treatments of neurological disorders, such as Alzheimer's disease and schizophrenia, but the high conservation of the acetylcholine-binding pocket has spurred current research into targeting allosteric sites on these receptors. Here we report the crystal structures of the M1 and M4 muscarinic receptors bound to the inverse agonist, tiotropium. Comparison of these structures with each other, as well as with the previously reported M2 and M3 receptor structures, reveals differences in the orthosteric and allosteric binding sites that contribute to a role in drug selectivity at this important receptor family. We also report identification of a cluster of residues that form a network linking the orthosteric and allosteric sites of the M4 receptor, which provides new insight into how allosteric modulation may be transmitted between the two spatially distinct domains.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thal, David M -- Sun, Bingfa -- Feng, Dan -- Nawaratne, Vindhya -- Leach, Katie -- Felder, Christian C -- Bures, Mark G -- Evans, David A -- Weis, William I -- Bachhawat, Priti -- Kobilka, Tong Sun -- Sexton, Patrick M -- Kobilka, Brian K -- Christopoulos, Arthur -- U19 GM106990/GM/NIGMS NIH HHS/ -- Y1-CO-1020/CO/NCI NIH HHS/ -- Y1-GM-1104/GM/NIGMS NIH HHS/ -- England -- Nature. 2016 Mar 17;531(7594):335-40. doi: 10.1038/nature17188. Epub 2016 Mar 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia. ; ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA. ; Neuroscience, Eli Lilly, Indianapolis, Indiana 46285, USA. ; Computational Chemistry and Chemoinformatics, Eli Lilly, Indianapolis, Indiana 46285, USA. ; Computational Chemistry and Chemoinformatics, Eli Lilly, Sunninghill Road, Windlesham GU20 6PH, UK. ; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA. ; Department of Structural Biology, 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/26958838" target="_blank"〉PubMed〈/a〉

Description: Integration of the reverse-transcribed viral DNA into the host genome is an essential step in the life cycle of retroviruses. Retrovirus integrase catalyses insertions of both ends of the linear viral DNA into a host chromosome. Integrase from HIV-1 and closely related retroviruses share the three-domain organization, consisting of a catalytic core domain flanked by amino- and carboxy-terminal domains essential for the concerted integration reaction. Although structures of the tetrameric integrase-DNA complexes have been reported for integrase from prototype foamy virus featuring an additional DNA-binding domain and longer interdomain linkers, the architecture of a canonical three-domain integrase bound to DNA remained elusive. Here we report a crystal structure of the three-domain integrase from Rous sarcoma virus in complex with viral and target DNAs. The structure shows an octameric assembly of integrase, in which a pair of integrase dimers engage viral DNA ends for catalysis while another pair of non-catalytic integrase dimers bridge between the two viral DNA molecules and help capture target DNA. The individual domains of the eight integrase molecules play varying roles to hold the complex together, making an extensive network of protein-DNA and protein-protein contacts that show both conserved and distinct features compared with those observed for prototype foamy virus integrase. Our work highlights the diversity of retrovirus intasome assembly and provides insights into the mechanisms of integration by HIV-1 and related retroviruses.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yin, Zhiqi -- Shi, Ke -- Banerjee, Surajit -- Pandey, Krishan K -- Bera, Sibes -- Grandgenett, Duane P -- Aihara, Hideki -- AI087098/AI/NIAID NIH HHS/ -- AI100682/AI/NIAID NIH HHS/ -- GM109770/GM/NIGMS NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- England -- Nature. 2016 Feb 18;530(7590):362-6. doi: 10.1038/nature16950.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA. ; Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, USA. ; Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA. ; Northeastern Collaborative Access Team, Cornell University, Advanced Photon Source, Lemont, Illinois 60439, USA. ; Institute for Molecular Virology, St. Louis University Health Sciences Center, St. Louis, Missouri 63104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26887497" target="_blank"〉PubMed〈/a〉

Description: The serotonin transporter (SERT) terminates serotonergic signalling through the sodium- and chloride-dependent reuptake of neurotransmitter into presynaptic neurons. SERT is a target for antidepressant and psychostimulant drugs, which block reuptake and prolong neurotransmitter signalling. Here we report X-ray crystallographic structures of human SERT at 3.15 A resolution bound to the antidepressants (S)-citalopram or paroxetine. Antidepressants lock SERT in an outward-open conformation by lodging in the central binding site, located between transmembrane helices 1, 3, 6, 8 and 10, directly blocking serotonin binding. We further identify the location of an allosteric site in the complex as residing at the periphery of the extracellular vestibule, interposed between extracellular loops 4 and 6 and transmembrane helices 1, 6, 10 and 11. Occupancy of the allosteric site sterically hinders ligand unbinding from the central site, providing an explanation for the action of (S)-citalopram as an allosteric ligand. These structures define the mechanism of antidepressant action in SERT, and provide blueprints for future drug design.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Coleman, Jonathan A -- Green, Evan M -- Gouaux, Eric -- 5R37MH070039/MH/NIMH NIH HHS/ -- R37 MH070039/MH/NIMH NIH HHS/ -- Canadian Institutes of Health Research/Canada -- Howard Hughes Medical Institute/ -- England -- Nature. 2016 Apr 21;532(7599):334-9. doi: 10.1038/nature17629. Epub 2016 Apr 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA. ; Howard Hughes Medical Institute, Oregon Health &Science University, Portland, Oregon 97239, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27049939" target="_blank"〉PubMed〈/a〉

Description: Two-pore channels (TPCs) comprise a subfamily (TPC1-3) of eukaryotic voltage- and ligand-gated cation channels with two non-equivalent tandem pore-forming subunits that dimerize to form quasi-tetramers. Found in vacuolar or endolysosomal membranes, they regulate the conductance of sodium and calcium ions, intravesicular pH, trafficking and excitability. TPCs are activated by a decrease in transmembrane potential and an increase in cytosolic calcium concentrations, are inhibited by low luminal pH and calcium, and are regulated by phosphorylation. Here we report the crystal structure of TPC1 from Arabidopsis thaliana at 2.87 A resolution as a basis for understanding ion permeation, channel activation, the location of voltage-sensing domains and regulatory ion-binding sites. We determined sites of phosphorylation in the amino-terminal and carboxy-terminal domains that are positioned to allosterically modulate cytoplasmic Ca(2+) activation. One of the two voltage-sensing domains (VSD2) encodes voltage sensitivity and inhibition by luminal Ca(2+) and adopts a conformation distinct from the activated state observed in structures of other voltage-gated ion channels. The structure shows that potent pharmacophore trans-Ned-19 (ref. 17) acts allosterically by clamping the pore domains to VSD2. In animals, Ned-19 prevents infection by Ebola virus and other filoviruses, presumably by altering their fusion with the endolysosome and delivery of their contents into the cytoplasm.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863712/" 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/PMC4863712/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kintzer, Alexander F -- Stroud, Robert M -- GM24485/GM/NIGMS NIH HHS/ -- P41-GM103311/GM/NIGMS NIH HHS/ -- P41-RR001614/RR/NCRR NIH HHS/ -- P41GM103393/GM/NIGMS NIH HHS/ -- R37 GM024485/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2016 Mar 10;531(7593):258-62. doi: 10.1038/nature17194.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26961658" target="_blank"〉PubMed〈/a〉

Description: Contractile tails are composed of an inner tube wrapped by an outer sheath assembled in an extended, metastable conformation that stores mechanical energy necessary for its contraction. Contraction is used to propel the rigid inner tube towards target cells for DNA or toxin delivery. Although recent studies have revealed the structure of the contractile sheath of the type VI secretion system, the mechanisms by which its polymerization is controlled and coordinated with the assembly of the inner tube remain unknown. Here we show that the starfish-like TssA dodecameric complex interacts with tube and sheath components. Fluorescence microscopy experiments in enteroaggregative Escherichia coli reveal that TssA binds first to the type VI secretion system membrane core complex and then initiates tail polymerization. TssA remains at the tip of the growing structure and incorporates new tube and sheath blocks. On the basis of these results, we propose that TssA primes and coordinates tail tube and sheath biogenesis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zoued, Abdelrahim -- Durand, Eric -- Brunet, Yannick R -- Spinelli, Silvia -- Douzi, Badreddine -- Guzzo, Mathilde -- Flaugnatti, Nicolas -- Legrand, Pierre -- Journet, Laure -- Fronzes, Remi -- Mignot, Tam -- Cambillau, Christian -- Cascales, Eric -- England -- Nature. 2016 Mar 3;531(7592):59-63. doi: 10.1038/nature17182. Epub 2016 Feb 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratoire d'Ingenierie des Systemes Macromoleculaires, Institut de Microbiologie de la Mediterranee, CNRS UMR7255, Aix-Marseille Universite, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. ; Architecture et Fonction des Macromolecules Biologiques, Centre National de la Recherche Scientifique, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France. ; Architecture et Fonction des Macromolecules Biologiques, Aix-Marseille Universite, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France. ; G5 Biologie structurale de la secretion bacterienne, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France. ; UMR 3528, CNRS, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France. ; Laboratoire de Chimie Bacterienne, Institut de Microbiologie de la Mediterranee, CNRS UMR7283, Aix-Marseille Universite, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. ; Synchrotron Soleil, L'Orme des merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette Cedex, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26909579" target="_blank"〉PubMed〈/a〉

Description: Polyketide synthases (PKSs) are biosynthetic factories that produce natural products with important biological and pharmacological activities. Their exceptional product diversity is encoded in a modular architecture. Modular PKSs (modPKSs) catalyse reactions colinear to the order of modules in an assembly line, whereas iterative PKSs (iPKSs) use a single module iteratively as exemplified by fungal iPKSs (fiPKSs). However, in some cases non-colinear iterative action is also observed for modPKSs modules and is controlled by the assembly line environment. PKSs feature a structural and functional separation into a condensing and a modifying region as observed for fatty acid synthases. Despite the outstanding relevance of PKSs, the detailed organization of PKSs with complete fully reducing modifying regions remains elusive. Here we report a hybrid crystal structure of Mycobacterium smegmatis mycocerosic acid synthase based on structures of its condensing and modifying regions. Mycocerosic acid synthase is a fully reducing iPKS, closely related to modPKSs, and the prototype of mycobacterial mycocerosic acid synthase-like PKSs. It is involved in the biosynthesis of C20-C28 branched-chain fatty acids, which are important virulence factors of mycobacteria. Our structural data reveal a dimeric linker-based organization of the modifying region and visualize dynamics and conformational coupling in PKSs. On the basis of comparative small-angle X-ray scattering, the observed modifying region architecture may be common also in modPKSs. The linker-based organization provides a rationale for the characteristic variability of PKS modules as a main contributor to product diversity. The comprehensive architectural model enables functional dissection and re-engineering of PKSs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Herbst, Dominik A -- Jakob, Roman P -- Zahringer, Franziska -- Maier, Timm -- England -- Nature. 2016 Mar 24;531(7595):533-7. doi: 10.1038/nature16993. Epub 2016 Mar 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26976449" target="_blank"〉PubMed〈/a〉

Description: Accurate chromosome segregation requires timely dissolution of chromosome cohesion after chromosomes are properly attached to the mitotic spindle. Separase is absolutely essential for cohesion dissolution in organisms from yeast to man. It cleaves the kleisin subunit of cohesin and opens the cohesin ring to allow chromosome segregation. Cohesin cleavage is spatiotemporally controlled by separase-associated regulatory proteins, including the inhibitory chaperone securin, and by phosphorylation of both the enzyme and substrates. Dysregulation of this process causes chromosome missegregation and aneuploidy, contributing to cancer and birth defects. Despite its essential functions, atomic structures of separase have not been determined. Here we report crystal structures of the separase protease domain from the thermophilic fungus Chaetomium thermophilum, alone or covalently bound to unphosphorylated and phosphorylated inhibitory peptides derived from a cohesin cleavage site. These structures reveal how separase recognizes cohesin and how cohesin phosphorylation by polo-like kinase 1 (Plk1) enhances cleavage. Consistent with a previous cellular study, mutating two securin residues in a conserved motif that partly matches the separase cleavage consensus converts securin from a separase inhibitor to a substrate. Our study establishes atomic mechanisms of substrate cleavage by separase and suggests competitive inhibition by securin.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847710/" 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/PMC4847710/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lin, Zhonghui -- Luo, Xuelian -- Yu, Hongtao -- GM107415/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2016 Apr 7;532(7597):131-4. doi: 10.1038/nature17402. Epub 2016 Mar 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA. ; Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA. ; Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, Texas 75390, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27027290" target="_blank"〉PubMed〈/a〉

Description: Bacteria secrete peptides and proteins to communicate, to poison competitors, and to manipulate host cells. Among the various protein-translocation machineries, the peptidase-containing ATP-binding cassette transporters (PCATs) are appealingly simple. Each PCAT contains two peptidase domains that cleave the secretion signal from the substrate, two transmembrane domains that form a translocation pathway, and two nucleotide-binding domains that hydrolyse ATP. In Gram-positive bacteria, PCATs function both as maturation proteases and exporters for quorum-sensing or antimicrobial polypeptides. In Gram-negative bacteria, PCATs interact with two other membrane proteins to form the type 1 secretion system. Here we present crystal structures of PCAT1 from Clostridium thermocellum in two different conformations. These structures, accompanied by biochemical data, show that the translocation pathway is a large alpha-helical barrel sufficient to accommodate small folded proteins. ATP binding alternates access to the transmembrane pathway and also regulates the protease activity, thereby coupling substrate processing to translocation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lin, David Yin-wei -- Huang, Shuo -- Chen, Jue -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Jul 23;523(7561):425-30. doi: 10.1038/nature14623.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Laboratory of Membrane Biology and Biophysics, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA [2] Howard Hughes Medical Institute, 1230 York Avenue, New York, New York 10065, USA. ; Howard Hughes Medical Institute, 1230 York Avenue, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26201595" target="_blank"〉PubMed〈/a〉

Description: Classical crystallography can determine structures as complicated as multi-component ribosomal assemblies with atomic resolution, but is inadequate for disordered systems--even those as simple as water ice--that occupy the complex middle ground between liquid-like randomness and crystalline periodic order. Correlated disorder nevertheless has clear crystallographic signatures that map to the type of disorder, irrespective of the underlying physical or chemical interactions and material involved. This mapping hints at a common language for disordered states that will help us to understand, control and exploit the disorder responsible for many interesting physical properties.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Keen, David A -- Goodwin, Andrew L -- England -- Nature. 2015 May 21;521(7552):303-9. doi: 10.1038/nature14453.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉ISIS Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, UK. ; Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25993960" target="_blank"〉PubMed〈/a〉

Description: Gene expression is regulated by transcription factors (TFs), proteins that recognize short DNA sequence motifs. Such sequences are very common in the human genome, and an important determinant of the specificity of gene expression is the cooperative binding of multiple TFs to closely located motifs. However, interactions between DNA-bound TFs have not been systematically characterized. To identify TF pairs that bind cooperatively to DNA, and to characterize their spacing and orientation preferences, we have performed consecutive affinity-purification systematic evolution of ligands by exponential enrichment (CAP-SELEX) analysis of 9,400 TF-TF-DNA interactions. This analysis revealed 315 TF-TF interactions recognizing 618 heterodimeric motifs, most of which have not been previously described. The observed cooperativity occurred promiscuously between TFs from diverse structural families. Structural analysis of the TF pairs, including a novel crystal structure of MEIS1 and DLX3 bound to their identified recognition site, revealed that the interactions between the TFs were predominantly mediated by DNA. Most TF pair sites identified involved a large overlap between individual TF recognition motifs, and resulted in recognition of composite sites that were markedly different from the individual TF's motifs. Together, our results indicate that the DNA molecule commonly plays an active role in cooperative interactions that define the gene regulatory lexicon.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jolma, Arttu -- Yin, Yimeng -- Nitta, Kazuhiro R -- Dave, Kashyap -- Popov, Alexander -- Taipale, Minna -- Enge, Martin -- Kivioja, Teemu -- Morgunova, Ekaterina -- Taipale, Jussi -- England -- Nature. 2015 Nov 19;527(7578):384-8. doi: 10.1038/nature15518. Epub 2015 Nov 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biosciences and Nutrition, Karolinska Institutet, SE 141 83, Sweden. ; European Synchrotron Radiation Facility, 38043 Grenoble, France. ; Genome-Scale Biology Program, University of Helsinki, P.O. Box 63, FI-00014, Finland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26550823" target="_blank"〉PubMed〈/a〉

Description: Rising temperatures and lessening fresh water supplies are threatening agricultural productivity and have motivated efforts to improve plant water use and drought tolerance. During water deficit, plants produce elevated levels of abscisic acid (ABA), which improves water consumption and stress tolerance by controlling guard cell aperture and other protective responses. One attractive strategy for controlling water use is to develop compounds that activate ABA receptors, but agonists approved for use have yet to be developed. In principle, an engineered ABA receptor that can be activated by an existing agrochemical could achieve this goal. Here we describe a variant of the ABA receptor PYRABACTIN RESISTANCE 1 (PYR1) that possesses nanomolar sensitivity to the agrochemical mandipropamid and demonstrate its efficacy for controlling ABA responses and drought tolerance in transgenic plants. Furthermore, crystallographic studies provide a mechanistic basis for its activity and demonstrate the relative ease with which the PYR1 ligand-binding pocket can be altered to accommodate new ligands. Thus, we have successfully repurposed an agrochemical for a new application using receptor engineering. We anticipate that this strategy will be applied to other plant receptors and represents a new avenue for crop improvement.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Park, Sang-Youl -- Peterson, Francis C -- Mosquna, Assaf -- Yao, Jin -- Volkman, Brian F -- Cutler, Sean R -- England -- Nature. 2015 Apr 23;520(7548):545-8. doi: 10.1038/nature14123. Epub 2015 Feb 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA [2] Institute for Integrative Genome Biology, Riverside, California 92521, USA. ; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25652827" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schimmel, Paul -- England -- Nature. 2015 May 21;521(7552):291. doi: 10.1038/521291a.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Scripps Research Institute in Jupiter, Florida, and La Jolla, California. He was a colleague of Alexander Rich at the Massachusetts Institute of Technology in Cambridge from 1967 onwards.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25993953" target="_blank"〉PubMed〈/a〉

Description: In response to adenosine 5'-diphosphate, the P2Y1 receptor (P2Y1R) facilitates platelet aggregation, and thus serves as an important antithrombotic drug target. Here we report the crystal structures of the human P2Y1R in complex with a nucleotide antagonist MRS2500 at 2.7 A resolution, and with a non-nucleotide antagonist BPTU at 2.2 A resolution. The structures reveal two distinct ligand-binding sites, providing atomic details of P2Y1R's unique ligand-binding modes. MRS2500 recognizes a binding site within the seven transmembrane bundle of P2Y1R, which is different in shape and location from the nucleotide binding site in the previously determined structure of P2Y12R, representative of another P2YR subfamily. BPTU binds to an allosteric pocket on the external receptor interface with the lipid bilayer, making it the first structurally characterized selective G-protein-coupled receptor (GPCR) ligand located entirely outside of the helical bundle. These high-resolution insights into P2Y1R should enable discovery of new orthosteric and allosteric antithrombotic drugs with reduced adverse effects.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408927/" 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/PMC4408927/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Dandan -- Gao, Zhan-Guo -- Zhang, Kaihua -- Kiselev, Evgeny -- Crane, Steven -- Wang, Jiang -- Paoletta, Silvia -- Yi, Cuiying -- Ma, Limin -- Zhang, Wenru -- Han, Gye Won -- Liu, Hong -- Cherezov, Vadim -- Katritch, Vsevolod -- Jiang, Hualiang -- Stevens, Raymond C -- Jacobson, Kenneth A -- Zhao, Qiang -- Wu, Beili -- U54 GM094618/GM/NIGMS NIH HHS/ -- U54GM094618/GM/NIGMS NIH HHS/ -- Z01 DK031116-21/Intramural NIH HHS/ -- Z01DK031116-26/DK/NIDDK NIH HHS/ -- ZIA DK031116-26/Intramural NIH HHS/ -- England -- Nature. 2015 Apr 16;520(7547):317-21. doi: 10.1038/nature14287. Epub 2015 Mar 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Pudong, Shanghai 201203, China. ; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ; Bridge Institute, Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA. ; Bridge Institute, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA. ; Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Pudong, Shanghai 201203, China. ; 1] Bridge Institute, Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA [2] Bridge Institute, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA [3] iHuman Institute, ShanghaiTech University, 99 Haike Road, Pudong, Shanghai 201203, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25822790" target="_blank"〉PubMed〈/a〉

Description: The plant hormone jasmonate plays crucial roles in regulating plant responses to herbivorous insects and microbial pathogens and is an important regulator of plant growth and development. Key mediators of jasmonate signalling include MYC transcription factors, which are repressed by jasmonate ZIM-domain (JAZ) transcriptional repressors in the resting state. In the presence of active jasmonate, JAZ proteins function as jasmonate co-receptors by forming a hormone-dependent complex with COI1, the F-box subunit of an SCF-type ubiquitin E3 ligase. The hormone-dependent formation of the COI1-JAZ co-receptor complex leads to ubiquitination and proteasome-dependent degradation of JAZ repressors and release of MYC proteins from transcriptional repression. The mechanism by which JAZ proteins repress MYC transcription factors and how JAZ proteins switch between the repressor function in the absence of hormone and the co-receptor function in the presence of hormone remain enigmatic. Here we show that Arabidopsis MYC3 undergoes pronounced conformational changes when bound to the conserved Jas motif of the JAZ9 repressor. The Jas motif, previously shown to bind to hormone as a partly unwound helix, forms a complete alpha-helix that displaces the amino (N)-terminal helix of MYC3 and becomes an integral part of the MYC N-terminal fold. In this position, the Jas helix competitively inhibits MYC3 interaction with the MED25 subunit of the transcriptional Mediator complex. Our structural and functional studies elucidate a dynamic molecular switch mechanism that governs the repression and activation of a major plant hormone pathway.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4567411/" 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/PMC4567411/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Feng -- Yao, Jian -- Ke, Jiyuan -- Zhang, Li -- Lam, Vinh Q -- Xin, Xiu-Fang -- Zhou, X Edward -- Chen, Jian -- Brunzelle, Joseph -- Griffin, Patrick R -- Zhou, Mingguo -- Xu, H Eric -- Melcher, Karsten -- He, Sheng Yang -- R01 AI068718/AI/NIAID NIH HHS/ -- R01 GM102545/GM/NIGMS NIH HHS/ -- R01AI060761/AI/NIAID NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Sep 10;525(7568):269-73. doi: 10.1038/nature14661. Epub 2015 Aug 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA. ; DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA. ; College of Plant Protection, Nanjing Agricultural University, No. 1 Weigang, 210095, Nanjing, Jiangsu Province, China. ; Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008, USA. ; Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA. ; Department of Molecular Therapeutics, Translational Research Institute, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA. ; College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China. ; Department of Molecular Pharmacology and Biological Chemistry, Life Sciences Collaborative Access Team, Synchrotron Research Center, Northwestern University, Argonne, Illinois 60439, USA. ; Key Laboratory of Receptor Research, VARI-SIMM Center, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China. ; Howard Hughes Medical Institute, Michigan State University, East Lansing, Michigan 48824, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26258305" target="_blank"〉PubMed〈/a〉

Description: The bacterial ubiD and ubiX or the homologous fungal fdc1 and pad1 genes have been implicated in the non-oxidative reversible decarboxylation of aromatic substrates, and play a pivotal role in bacterial ubiquinone (also known as coenzyme Q) biosynthesis or microbial biodegradation of aromatic compounds, respectively. Despite biochemical studies on individual gene products, the composition and cofactor requirement of the enzyme responsible for in vivo decarboxylase activity remained unclear. Here we show that Fdc1 is solely responsible for the reversible decarboxylase activity, and that it requires a new type of cofactor: a prenylated flavin synthesized by the associated UbiX/Pad1. Atomic resolution crystal structures reveal that two distinct isomers of the oxidized cofactor can be observed, an isoalloxazine N5-iminium adduct and a N5 secondary ketimine species with markedly altered ring structure, both having azomethine ylide character. Substrate binding positions the dipolarophile enoic acid group directly above the azomethine ylide group. The structure of a covalent inhibitor-cofactor adduct suggests that 1,3-dipolar cycloaddition chemistry supports reversible decarboxylation in these enzymes. Although 1,3-dipolar cycloaddition is commonly used in organic chemistry, we propose that this presents the first example, to our knowledge, of an enzymatic 1,3-dipolar cycloaddition reaction. Our model for Fdc1/UbiD catalysis offers new routes in alkene hydrocarbon production or aryl (de)carboxylation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Payne, Karl A P -- White, Mark D -- Fisher, Karl -- Khara, Basile -- Bailey, Samuel S -- Parker, David -- Rattray, Nicholas J W -- Trivedi, Drupad K -- Goodacre, Royston -- Beveridge, Rebecca -- Barran, Perdita -- Rigby, Stephen E J -- Scrutton, Nigel S -- Hay, Sam -- Leys, David -- BB/K017802/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/M/017702/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2015 Jun 25;522(7557):497-501. doi: 10.1038/nature14560. Epub 2015 Jun 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Synthetic Biology of Fine and Speciality Chemicals, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. ; Innovation/Biodomain, Shell International Exploration and Production, Westhollow Technology Center, 3333 Highway 6 South, Houston, Texas 77082-3101, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26083754" target="_blank"〉PubMed〈/a〉

Description: V(D)J recombination in the vertebrate immune system generates a highly diverse population of immunoglobulins and T-cell receptors by combinatorial joining of segments of coding DNA. The RAG1-RAG2 protein complex initiates this site-specific recombination by cutting DNA at specific sites flanking the coding segments. Here we report the crystal structure of the mouse RAG1-RAG2 complex at 3.2 A resolution. The 230-kilodalton RAG1-RAG2 heterotetramer is 'Y-shaped', with the amino-terminal domains of the two RAG1 chains forming an intertwined stalk. Each RAG1-RAG2 heterodimer composes one arm of the 'Y', with the active site in the middle and RAG2 at its tip. The RAG1-RAG2 structure rationalizes more than 60 mutations identified in immunodeficient patients, as well as a large body of genetic and biochemical data. The architectural similarity between RAG1 and the hairpin-forming transposases Hermes and Tn5 suggests the evolutionary conservation of these DNA rearrangements.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342785/" 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/PMC4342785/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, Min-Sung -- Lapkouski, Mikalai -- Yang, Wei -- Gellert, Martin -- Z01 DK036147-01/Intramural NIH HHS/ -- Z01 DK036147-02/Intramural NIH HHS/ -- Z01 DK036167-01/Intramural NIH HHS/ -- Z01 DK036167-02/Intramural NIH HHS/ -- ZIA DK036147-03/Intramural NIH HHS/ -- ZIA DK036147-04/Intramural NIH HHS/ -- ZIA DK036147-05/Intramural NIH HHS/ -- ZIA DK036147-06/Intramural NIH HHS/ -- ZIA DK036147-07/Intramural NIH HHS/ -- ZIA DK036147-08/Intramural NIH HHS/ -- ZIA DK036167-03/Intramural NIH HHS/ -- ZIA DK036167-04/Intramural NIH HHS/ -- ZIA DK036167-05/Intramural NIH HHS/ -- ZIA DK036167-06/Intramural NIH HHS/ -- ZIA DK036167-07/Intramural NIH HHS/ -- England -- Nature. 2015 Feb 26;518(7540):507-11. doi: 10.1038/nature14174. Epub 2015 Feb 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25707801" target="_blank"〉PubMed〈/a〉

Description: The BCR-ABL1 fusion gene is a driver oncogene in chronic myeloid leukaemia and 30-50% of cases of adult acute lymphoblastic leukaemia. Introduction of ABL1 kinase inhibitors (for example, imatinib) has markedly improved patient survival, but acquired drug resistance remains a challenge. Point mutations in the ABL1 kinase domain weaken inhibitor binding and represent the most common clinical resistance mechanism. The BCR-ABL1 kinase domain gatekeeper mutation Thr315Ile (T315I) confers resistance to all approved ABL1 inhibitors except ponatinib, which has toxicity limitations. Here we combine comprehensive drug sensitivity and resistance profiling of patient cells ex vivo with structural analysis to establish the VEGFR tyrosine kinase inhibitor axitinib as a selective and effective inhibitor for T315I-mutant BCR-ABL1-driven leukaemia. Axitinib potently inhibited BCR-ABL1(T315I), at both biochemical and cellular levels, by binding to the active form of ABL1(T315I) in a mutation-selective binding mode. These findings suggest that the T315I mutation shifts the conformational equilibrium of the kinase in favour of an active (DFG-in) A-loop conformation, which has more optimal binding interactions with axitinib. Treatment of a T315I chronic myeloid leukaemia patient with axitinib resulted in a rapid reduction of T315I-positive cells from bone marrow. Taken together, our findings demonstrate an unexpected opportunity to repurpose axitinib, an anti-angiogenic drug approved for renal cancer, as an inhibitor for ABL1 gatekeeper mutant drug-resistant leukaemia patients. This study shows that wild-type proteins do not always sample the conformations available to disease-relevant mutant proteins and that comprehensive drug testing of patient-derived cells can identify unpredictable, clinically significant drug-repositioning opportunities.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pemovska, Tea -- Johnson, Eric -- Kontro, Mika -- Repasky, Gretchen A -- Chen, Jeffrey -- Wells, Peter -- Cronin, Ciaran N -- McTigue, Michele -- Kallioniemi, Olli -- Porkka, Kimmo -- Murray, Brion W -- Wennerberg, Krister -- England -- Nature. 2015 Mar 5;519(7541):102-5. doi: 10.1038/nature14119. Epub 2015 Feb 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00290 Helsinki, Finland. ; La Jolla Laboratories, Pfizer Worldwide Research &Development, San Diego, California 92121, USA. ; Hematology Research Unit Helsinki, University of Helsinki, and Helsinki University Hospital Comprehensive Cancer Center, Department of Hematology, 00290 Helsinki, Finland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25686603" target="_blank"〉PubMed〈/a〉

Description: Anaerobic ammonium oxidation (anammox) has a major role in the Earth's nitrogen cycle and is used in energy-efficient wastewater treatment. This bacterial process combines nitrite and ammonium to form dinitrogen (N2) gas, and has been estimated to synthesize up to 50% of the dinitrogen gas emitted into our atmosphere from the oceans. Strikingly, the anammox process relies on the highly unusual, extremely reactive intermediate hydrazine, a compound also used as a rocket fuel because of its high reducing power. So far, the enzymatic mechanism by which hydrazine is synthesized is unknown. Here we report the 2.7 A resolution crystal structure, as well as biophysical and spectroscopic studies, of a hydrazine synthase multiprotein complex isolated from the anammox organism Kuenenia stuttgartiensis. The structure shows an elongated dimer of heterotrimers, each of which has two unique c-type haem-containing active sites, as well as an interaction point for a redox partner. Furthermore, a system of tunnels connects these active sites. The crystal structure implies a two-step mechanism for hydrazine synthesis: a three-electron reduction of nitric oxide to hydroxylamine at the active site of the gamma-subunit and its subsequent condensation with ammonia, yielding hydrazine in the active centre of the alpha-subunit. Our results provide the first, to our knowledge, detailed structural insight into the mechanism of biological hydrazine synthesis, which is of major significance for our understanding of the conversion of nitrogenous compounds in nature.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dietl, Andreas -- Ferousi, Christina -- Maalcke, Wouter J -- Menzel, Andreas -- de Vries, Simon -- Keltjens, Jan T -- Jetten, Mike S M -- Kartal, Boran -- Barends, Thomas R M -- P41-GM103311/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Nov 19;527(7578):394-7. doi: 10.1038/nature15517. Epub 2015 Oct 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany. ; Department of Microbiology, Institute for Water and Wetland Research, Radboud University Nijmegen, 6525 AJ Nijmegen, The Netherlands. ; Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland. ; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands. ; Department of Biochemistry and Microbiology, Laboratory of Microbiology, Gent University, Gent, Belgium.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26479033" target="_blank"〉PubMed〈/a〉

Description: Synaptotagmin-1 and neuronal SNARE proteins have central roles in evoked synchronous neurotransmitter release; however, it is unknown how they cooperate to trigger synaptic vesicle fusion. Here we report atomic-resolution crystal structures of Ca(2+)- and Mg(2+)-bound complexes between synaptotagmin-1 and the neuronal SNARE complex, one of which was determined with diffraction data from an X-ray free-electron laser, leading to an atomic-resolution structure with accurate rotamer assignments for many side chains. The structures reveal several interfaces, including a large, specific, Ca(2+)-independent and conserved interface. Tests of this interface by mutagenesis suggest that it is essential for Ca(2+)-triggered neurotransmitter release in mouse hippocampal neuronal synapses and for Ca(2+)-triggered vesicle fusion in a reconstituted system. We propose that this interface forms before Ca(2+) triggering, moves en bloc as Ca(2+) influx promotes the interactions between synaptotagmin-1 and the plasma membrane, and consequently remodels the membrane to promote fusion, possibly in conjunction with other interfaces.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4607316/" 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/PMC4607316/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhou, Qiangjun -- Lai, Ying -- Bacaj, Taulant -- Zhao, Minglei -- Lyubimov, Artem Y -- Uervirojnangkoorn, Monarin -- Zeldin, Oliver B -- Brewster, Aaron S -- Sauter, Nicholas K -- Cohen, Aina E -- Soltis, S Michael -- Alonso-Mori, Roberto -- Chollet, Matthieu -- Lemke, Henrik T -- Pfuetzner, Richard A -- Choi, Ucheor B -- Weis, William I -- Diao, Jiajie -- Sudhof, Thomas C -- Brunger, Axel T -- GM095887/GM/NIGMS NIH HHS/ -- GM102520/GM/NIGMS NIH HHS/ -- MH086403/MH/NIMH NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- P41GM103393/GM/NIGMS NIH HHS/ -- P50 MH086403/MH/NIMH NIH HHS/ -- R01 GM077071/GM/NIGMS NIH HHS/ -- R01 GM095887/GM/NIGMS NIH HHS/ -- R01 GM102520/GM/NIGMS NIH HHS/ -- R37 MH063105/MH/NIMH NIH HHS/ -- R37MH63105/MH/NIMH NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Sep 3;525(7567):62-7. doi: 10.1038/nature14975. Epub 2015 Aug 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA. ; Departments of Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, California 94305, USA. ; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. ; SLAC National Accelerator Laboratory, Stanford, California 94305, USA. ; Departments of Structural Biology, Molecular and Cellular Physiology, and Photon Science, Stanford University, Stanford, California 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26280336" target="_blank"〉PubMed〈/a〉

Description: The flipping of membrane-embedded lipids containing large, polar head groups is slow and energetically unfavourable, and is therefore catalysed by flippases, the mechanisms of which are unknown. A prominent example of a flipping reaction is the translocation of lipid-linked oligosaccharides that serve as donors in N-linked protein glycosylation. In Campylobacter jejuni, this process is catalysed by the ABC transporter PglK. Here we present a mechanism of PglK-catalysed lipid-linked oligosaccharide flipping based on crystal structures in distinct states, a newly devised in vitro flipping assay, and in vivo studies. PglK can adopt inward- and outward-facing conformations in vitro, but only outward-facing states are required for flipping. While the pyrophosphate-oligosaccharide head group of lipid-linked oligosaccharides enters the translocation cavity and interacts with positively charged side chains, the lipidic polyprenyl tail binds and activates the transporter but remains exposed to the lipid bilayer during the reaction. The proposed mechanism is distinct from the classical alternating-access model applied to other transporters.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Perez, Camilo -- Gerber, Sabina -- Boilevin, Jeremy -- Bucher, Monika -- Darbre, Tamis -- Aebi, Markus -- Reymond, Jean-Louis -- Locher, Kaspar P -- England -- Nature. 2015 Aug 27;524(7566):433-8. doi: 10.1038/nature14953. Epub 2015 Aug 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland. ; Department of Chemistry and Biochemistry, University of Berne, CH-3012 Berne, Switzerland. ; Institute of Microbiology, ETH Zurich, CH-8093 Zurich, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26266984" target="_blank"〉PubMed〈/a〉

Description: Methane-oxidizing bacteria (methanotrophs) require large quantities of copper for the membrane-bound (particulate) methane monooxygenase. Certain methanotrophs are also able to switch to using the iron-containing soluble methane monooxygenase to catalyse methane oxidation, with this switchover regulated by copper. Methane monooxygenases are nature's primary biological mechanism for suppressing atmospheric levels of methane, a potent greenhouse gas. Furthermore, methanotrophs and methane monooxygenases have enormous potential in bioremediation and for biotransformations producing bulk and fine chemicals, and in bioenergy, particularly considering increased methane availability from renewable sources and hydraulic fracturing of shale rock. Here we discover and characterize a novel copper storage protein (Csp1) from the methanotroph Methylosinus trichosporium OB3b that is exported from the cytosol, and stores copper for particulate methane monooxygenase. Csp1 is a tetramer of four-helix bundles with each monomer binding up to 13 Cu(I) ions in a previously unseen manner via mainly Cys residues that point into the core of the bundle. Csp1 is the first example of a protein that stores a metal within an established protein-folding motif. This work provides a detailed insight into how methanotrophs accumulate copper for the oxidation of methane. Understanding this process is essential if the wide-ranging biotechnological applications of methanotrophs are to be realized. Cytosolic homologues of Csp1 are present in diverse bacteria, thus challenging the dogma that such organisms do not use copper in this location.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561512/" 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/PMC4561512/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vita, Nicolas -- Platsaki, Semeli -- Basle, Arnaud -- Allen, Stephen J -- Paterson, Neil G -- Crombie, Andrew T -- Murrell, J Colin -- Waldron, Kevin J -- Dennison, Christopher -- 098375/Z/12/Z/Wellcome Trust/United Kingdom -- England -- Nature. 2015 Sep 3;525(7567):140-3. doi: 10.1038/nature14854. Epub 2015 Aug 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK. ; Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK. ; School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26308900" target="_blank"〉PubMed〈/a〉

Description: Tandem repeat proteins, which are formed by repetition of modular units of protein sequence and structure, play important biological roles as macromolecular binding and scaffolding domains, enzymes, and building blocks for the assembly of fibrous materials. The modular nature of repeat proteins enables the rapid construction and diversification of extended binding surfaces by duplication and recombination of simple building blocks. The overall architecture of tandem repeat protein structures--which is dictated by the internal geometry and local packing of the repeat building blocks--is highly diverse, ranging from extended, super-helical folds that bind peptide, DNA, and RNA partners, to closed and compact conformations with internal cavities suitable for small molecule binding and catalysis. Here we report the development and validation of computational methods for de novo design of tandem repeat protein architectures driven purely by geometric criteria defining the inter-repeat geometry, without reference to the sequences and structures of existing repeat protein families. We have applied these methods to design a series of closed alpha-solenoid repeat structures (alpha-toroids) in which the inter-repeat packing geometry is constrained so as to juxtapose the amino (N) and carboxy (C) termini; several of these designed structures have been validated by X-ray crystallography. Unlike previous approaches to tandem repeat protein engineering, our design procedure does not rely on template sequence or structural information taken from natural repeat proteins and hence can produce structures unlike those seen in nature. As an example, we have successfully designed and validated closed alpha-solenoid repeats with a left-handed helical architecture that--to our knowledge--is not yet present in the protein structure database.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727831/" 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/PMC4727831/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Doyle, Lindsey -- Hallinan, Jazmine -- Bolduc, Jill -- Parmeggiani, Fabio -- Baker, David -- Stoddard, Barry L -- Bradley, Philip -- R01 GM049857/GM/NIGMS NIH HHS/ -- R01 GM115545/GM/NIGMS NIH HHS/ -- R01GM49857/GM/NIGMS NIH HHS/ -- R21 GM106117/GM/NIGMS NIH HHS/ -- R21GM106117/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Dec 24;528(7583):585-8. doi: 10.1038/nature16191. Epub 2015 Dec 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, Washington 98109, USA. ; Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA. ; Institute for Protein Design, University of Washington, Seattle, Washington 98195, USA. ; Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA. ; Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, Washington 98019, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26675735" target="_blank"〉PubMed〈/a〉

Description: Phosphorus is required for all life and microorganisms can extract it from their environment through several metabolic pathways. When phosphate is in limited supply, some bacteria are able to use phosphonate compounds, which require specialized enzymatic machinery to break the stable carbon-phosphorus (C-P) bond. Despite its importance, the details of how this machinery catabolizes phosphonates remain unknown. Here we determine the crystal structure of the 240-kilodalton Escherichia coli C-P lyase core complex (PhnG-PhnH-PhnI-PhnJ; PhnGHIJ), and show that it is a two-fold symmetric hetero-octamer comprising an intertwined network of subunits with unexpected self-homologies. It contains two potential active sites that probably couple phosphonate compounds to ATP and subsequently hydrolyse the C-P bond. We map the binding site of PhnK on the complex using electron microscopy, and show that it binds to a conserved insertion domain of PhnJ. Our results provide a structural basis for understanding microbial phosphonate breakdown.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4617613/" 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/PMC4617613/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Seweryn, Paulina -- Van, Lan Bich -- Kjeldgaard, Morten -- Russo, Christopher J -- Passmore, Lori A -- Hove-Jensen, Bjarne -- Jochimsen, Bjarne -- Brodersen, Ditlev E -- MC_U105192715/Medical Research Council/United Kingdom -- England -- Nature. 2015 Sep 3;525(7567):68-72. doi: 10.1038/nature14683. Epub 2015 Aug 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark. ; Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26280334" target="_blank"〉PubMed〈/a〉

Description: Stearoyl-CoA desaturase (SCD) is conserved in all eukaryotes and introduces the first double bond into saturated fatty acyl-CoAs. Because the monounsaturated products of SCD are key precursors of membrane phospholipids, cholesterol esters and triglycerides, SCD is pivotal in fatty acid metabolism. Humans have two SCD homologues (SCD1 and SCD5), while mice have four (SCD1-SCD4). SCD1-deficient mice do not become obese or diabetic when fed a high-fat diet because of improved lipid metabolic profiles and insulin sensitivity. Thus, SCD1 is a pharmacological target in the treatment of obesity, diabetes and other metabolic diseases. SCD1 is an integral membrane protein located in the endoplasmic reticulum, and catalyses the formation of a cis-double bond between the ninth and tenth carbons of stearoyl- or palmitoyl-CoA. The reaction requires molecular oxygen, which is activated by a di-iron centre, and cytochrome b5, which regenerates the di-iron centre. To understand better the structural basis of these characteristics of SCD function, here we crystallize and solve the structure of mouse SCD1 bound to stearoyl-CoA at 2.6 A resolution. The structure shows a novel fold comprising four transmembrane helices capped by a cytosolic domain, and a plausible pathway for lateral substrate access and product egress. The acyl chain of the bound stearoyl-CoA is enclosed in a tunnel buried in the cytosolic domain, and the geometry of the tunnel and the conformation of the bound acyl chain provide a structural basis for the regioselectivity and stereospecificity of the desaturation reaction. The dimetal centre is coordinated by a unique spacial arrangement of nine conserved histidine residues that implies a potentially novel mechanism for oxygen activation. The structure also illustrates a possible route for electron transfer from cytochrome b5 to the di-iron centre.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689147/" 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/PMC4689147/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bai, Yonghong -- McCoy, Jason G -- Levin, Elena J -- Sobrado, Pablo -- Rajashankar, Kanagalaghatta R -- Fox, Brian G -- Zhou, Ming -- P41 GM103403/GM/NIGMS NIH HHS/ -- P41GM103403/GM/NIGMS NIH HHS/ -- R01 DK088057/DK/NIDDK NIH HHS/ -- R01 GM098878/GM/NIGMS NIH HHS/ -- R01 HL086392/HL/NHLBI NIH HHS/ -- R01DK088057/DK/NIDDK NIH HHS/ -- R01GM050853/GM/NIGMS NIH HHS/ -- R01GM098878/GM/NIGMS NIH HHS/ -- R01HL086392/HL/NHLBI NIH HHS/ -- U54 GM094584/GM/NIGMS NIH HHS/ -- U54GM094584/GM/NIGMS NIH HHS/ -- U54GM095315/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Aug 13;524(7564):252-6. doi: 10.1038/nature14549. Epub 2015 Jun 22.〈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. ; Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. ; NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois 60439, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26098370" target="_blank"〉PubMed〈/a〉

Description: Ubiquinone (also known as coenzyme Q) is a ubiquitous lipid-soluble redox cofactor that is an essential component of electron transfer chains. Eleven genes have been implicated in bacterial ubiquinone biosynthesis, including ubiX and ubiD, which are responsible for decarboxylation of the 3-octaprenyl-4-hydroxybenzoate precursor. Despite structural and biochemical characterization of UbiX as a flavin mononucleotide (FMN)-binding protein, no decarboxylase activity has been detected. Here we report that UbiX produces a novel flavin-derived cofactor required for the decarboxylase activity of UbiD. UbiX acts as a flavin prenyltransferase, linking a dimethylallyl moiety to the flavin N5 and C6 atoms. This adds a fourth non-aromatic ring to the flavin isoalloxazine group. In contrast to other prenyltransferases, UbiX is metal-independent and requires dimethylallyl-monophosphate as substrate. Kinetic crystallography reveals that the prenyltransferase mechanism of UbiX resembles that of the terpene synthases. The active site environment is dominated by pi systems, which assist phosphate-C1' bond breakage following FMN reduction, leading to formation of the N5-C1' bond. UbiX then acts as a chaperone for adduct reorientation, via transient carbocation species, leading ultimately to formation of the dimethylallyl C3'-C6 bond. Our findings establish the mechanism for formation of a new flavin-derived cofactor, extending both flavin and terpenoid biochemical repertoires.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉White, Mark D -- Payne, Karl A P -- Fisher, Karl -- Marshall, Stephen A -- Parker, David -- Rattray, Nicholas J W -- Trivedi, Drupad K -- Goodacre, Royston -- Rigby, Stephen E J -- Scrutton, Nigel S -- Hay, Sam -- Leys, David -- BB/K017802/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/M017702/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2015 Jun 25;522(7557):502-6. doi: 10.1038/nature14559. Epub 2015 Jun 17.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Synthetic Biology of Fine and Speciality Chemicals, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK. ; Innovation/Biodomain, Shell International Exploration and Production, Westhollow Technology Center, 3333 Highway 6 South, Houston, Texas 77082-3101, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26083743" target="_blank"〉PubMed〈/a〉

Description: To contend with hazards posed by environmental fluoride, microorganisms export this anion through F(-)-specific ion channels of the Fluc family. Since the recent discovery of Fluc channels, numerous idiosyncratic features of these proteins have been unearthed, including strong selectivity for F(-) over Cl(-) and dual-topology dimeric assembly. To understand the chemical basis for F(-) permeation and how the antiparallel subunits convene to form a F(-)-selective pore, here we solve the crystal structures of two bacterial Fluc homologues in complex with three different monobody inhibitors, with and without F(-) present, to a maximum resolution of 2.1 A. The structures reveal a surprising 'double-barrelled' channel architecture in which two F(-) ion pathways span the membrane, and the dual-topology arrangement includes a centrally coordinated cation, most likely Na(+). F(-) selectivity is proposed to arise from the very narrow pores and an unusual anion coordination that exploits the quadrupolar edges of conserved phenylalanine rings.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stockbridge, Randy B -- Kolmakova-Partensky, Ludmila -- Shane, Tania -- Koide, Akiko -- Koide, Shohei -- Miller, Christopher -- Newstead, Simon -- 102890/Z/13/Z/Wellcome Trust/United Kingdom -- K99 GM111767/GM/NIGMS NIH HHS/ -- K99-GM-111767/GM/NIGMS NIH HHS/ -- R01 GM107023/GM/NIGMS NIH HHS/ -- R01-GM107023/GM/NIGMS NIH HHS/ -- U54 GM087519/GM/NIGMS NIH HHS/ -- U54-GM087519/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Sep 24;525(7570):548-51. doi: 10.1038/nature14981. Epub 2015 Sep 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA. ; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA. ; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford OX1 3QU, UK. ; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26344196" target="_blank"〉PubMed〈/a〉

Description: DNA methylation is an important epigenetic modification. Ten-eleven translocation (TET) proteins are involved in DNA demethylation through iteratively oxidizing 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Here we show that human TET1 and TET2 are more active on 5mC-DNA than 5hmC/5fC-DNA substrates. We determine the crystal structures of TET2-5hmC-DNA and TET2-5fC-DNA complexes at 1.80 A and 1.97 A resolution, respectively. The cytosine portion of 5hmC/5fC is specifically recognized by TET2 in a manner similar to that of 5mC in the TET2-5mC-DNA structure, and the pyrimidine base of 5mC/5hmC/5fC adopts an almost identical conformation within the catalytic cavity. However, the hydroxyl group of 5hmC and carbonyl group of 5fC face towards the opposite direction because the hydroxymethyl group of 5hmC and formyl group of 5fC adopt restrained conformations through forming hydrogen bonds with the 1-carboxylate of NOG and N4 exocyclic nitrogen of cytosine, respectively. Biochemical analyses indicate that the substrate preference of TET2 results from the different efficiencies of hydrogen abstraction in TET2-mediated oxidation. The restrained conformation of 5hmC and 5fC within the catalytic cavity may prevent their abstractable hydrogen(s) adopting a favourable orientation for hydrogen abstraction and thus result in low catalytic efficiency. Our studies demonstrate that the substrate preference of TET2 results from the intrinsic value of its substrates at their 5mC derivative groups and suggest that 5hmC is relatively stable and less prone to further oxidation by TET proteins. Therefore, TET proteins are evolutionarily tuned to be less reactive towards 5hmC and facilitate the generation of 5hmC as a potentially stable mark for regulatory functions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hu, Lulu -- Lu, Junyan -- Cheng, Jingdong -- Rao, Qinhui -- Li, Ze -- Hou, Haifeng -- Lou, Zhiyong -- Zhang, Lei -- Li, Wei -- Gong, Wei -- Liu, Mengjie -- Sun, Chang -- Yin, Xiaotong -- Li, Jie -- Tan, Xiangshi -- Wang, Pengcheng -- Wang, Yinsheng -- Fang, Dong -- Cui, Qiang -- Yang, Pengyuan -- He, Chuan -- Jiang, Hualiang -- Luo, Cheng -- Xu, Yanhui -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Nov 5;527(7576):118-22. doi: 10.1038/nature15713. Epub 2015 Oct 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Fudan University Shanghai Cancer Center, Institute of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China. ; Key Laboratory of Molecular Medicine, Ministry of Education, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China. ; State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China. ; Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. ; Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. ; Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China. ; MOE Laboratory of Protein Science, School of Medicine, Tsinghua University, Beijing 100084, China. ; Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, USA. ; Theoretical Chemistry Institute, Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA. ; Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA. ; Howard Hughes Medical Institute, 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/26524525" target="_blank"〉PubMed〈/a〉

Description: Negative-sense RNA viruses, such as influenza, encode large, multidomain RNA-dependent RNA polymerases that can both transcribe and replicate the viral RNA genome. In influenza virus, the polymerase (FluPol) is composed of three polypeptides: PB1, PB2 and PA/P3. PB1 houses the polymerase active site, whereas PB2 and PA/P3 contain, respectively, cap-binding and endonuclease domains required for transcription initiation by cap-snatching. Replication occurs through de novo initiation and involves a complementary RNA intermediate. Currently available structures of the influenza A and B virus polymerases include promoter RNA (the 5' and 3' termini of viral genome segments), showing FluPol in transcription pre-initiation states. Here we report the structure of apo-FluPol from an influenza C virus, solved by X-ray crystallography to 3.9 A, revealing a new 'closed' conformation. The apo-FluPol forms a compact particle with PB1 at its centre, capped on one face by PB2 and clamped between the two globular domains of P3. Notably, this structure is radically different from those of promoter-bound FluPols. The endonuclease domain of P3 and the domains within the carboxy-terminal two-thirds of PB2 are completely rearranged. The cap-binding site is occluded by PB2, resulting in a conformation that is incompatible with transcription initiation. Thus, our structure captures FluPol in a closed, transcription pre-activation state. This reveals the conformation of newly made apo-FluPol in an infected cell, but may also apply to FluPol in the context of a non-transcribing ribonucleoprotein complex. Comparison of the apo-FluPol structure with those of promoter-bound FluPols allows us to propose a mechanism for FluPol activation. Our study demonstrates the remarkable flexibility of influenza virus RNA polymerase, and aids our understanding of the mechanisms controlling transcription and genome replication.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hengrung, Narin -- El Omari, Kamel -- Serna Martin, Itziar -- Vreede, Frank T -- Cusack, Stephen -- Rambo, Robert P -- Vonrhein, Clemens -- Bricogne, Gerard -- Stuart, David I -- Grimes, Jonathan M -- Fodor, Ervin -- 075491/Z/04/Wellcome Trust/United Kingdom -- 092931/Z/10/Z/Wellcome Trust/United Kingdom -- G1000099/Medical Research Council/United Kingdom -- G1100138/Medical Research Council/United Kingdom -- MR/K000241/1/Medical Research Council/United Kingdom -- England -- Nature. 2015 Nov 5;527(7576):114-7. doi: 10.1038/nature15525. Epub 2015 Oct 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK. ; Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Oxford OX3 7BN, UK. ; European Molecular Biology Laboratory, Grenoble Outstation and University Grenoble Alpes-Centre National de la Recherche Scientifique-EMBL Unit of Virus Host-Cell Interactions, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France. ; Diamond Light Source Ltd, Harwell Science &Innovation Campus, Didcot OX11 0DE, UK. ; Global Phasing Ltd, Sheraton House, Castle Park, Cambridge CB3 0AX, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26503046" target="_blank"〉PubMed〈/a〉

Description: The mechanochemical protein dynamin is the prototype of the dynamin superfamily of large GTPases, which shape and remodel membranes in diverse cellular processes. Dynamin forms predominantly tetramers in the cytosol, which oligomerize at the neck of clathrin-coated vesicles to mediate constriction and subsequent scission of the membrane. Previous studies have described the architecture of dynamin dimers, but the molecular determinants for dynamin assembly and its regulation have remained unclear. Here we present the crystal structure of the human dynamin tetramer in the nucleotide-free state. Combining structural data with mutational studies, oligomerization measurements and Markov state models of molecular dynamics simulations, we suggest a mechanism by which oligomerization of dynamin is linked to the release of intramolecular autoinhibitory interactions. We elucidate how mutations that interfere with tetramer formation and autoinhibition can lead to the congenital muscle disorders Charcot-Marie-Tooth neuropathy and centronuclear myopathy, respectively. Notably, the bent shape of the tetramer explains how dynamin assembles into a right-handed helical oligomer of defined diameter, which has direct implications for its function in membrane constriction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reubold, Thomas F -- Faelber, Katja -- Plattner, Nuria -- Posor, York -- Ketel, Katharina -- Curth, Ute -- Schlegel, Jeanette -- Anand, Roopsee -- Manstein, Dietmar J -- Noe, Frank -- Haucke, Volker -- Daumke, Oliver -- Eschenburg, Susanne -- England -- Nature. 2015 Sep 17;525(7569):404-8. doi: 10.1038/nature14880. Epub 2015 Aug 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Biophysikalische Chemie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. ; Max-Delbruck-Centrum fur Molekulare Medizin, Kristallographie, Robert-Rossle-Strasse 10, 13125 Berlin, Germany. ; Institut fur Mathematik, Freie Universitat Berlin, Arnimallee 6, 14195 Berlin, Germany. ; Leibniz-Institut fur Molekulare Pharmakologie, Robert-Rossle-Strasse 10, 13125 Berlin, Germany. ; Forschungseinrichtung Strukturanalyse, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. ; Institut fur Chemie und Biochemie, Freie Universitat Berlin, Takustrasse 6, 14195 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26302298" target="_blank"〉PubMed〈/a〉

Description: Activation of the mu-opioid receptor (muOR) is responsible for the efficacy of the most effective analgesics. To shed light on the structural basis for muOR activation, here we report a 2.1 A X-ray crystal structure of the murine muOR bound to the morphinan agonist BU72 and a G protein mimetic camelid antibody fragment. The BU72-stabilized changes in the muOR binding pocket are subtle and differ from those observed for agonist-bound structures of the beta2-adrenergic receptor (beta2AR) and the M2 muscarinic receptor. Comparison with active beta2AR reveals a common rearrangement in the packing of three conserved amino acids in the core of the muOR, and molecular dynamics simulations illustrate how the ligand-binding pocket is conformationally linked to this conserved triad. Additionally, an extensive polar network between the ligand-binding pocket and the cytoplasmic domains appears to play a similar role in signal propagation for all three G-protein-coupled receptors.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4639397/" 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/PMC4639397/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Weijiao -- Manglik, Aashish -- Venkatakrishnan, A J -- Laeremans, Toon -- Feinberg, Evan N -- Sanborn, Adrian L -- Kato, Hideaki E -- Livingston, Kathryn E -- Thorsen, Thor S -- Kling, Ralf C -- Granier, Sebastien -- Gmeiner, Peter -- Husbands, Stephen M -- Traynor, John R -- Weis, William I -- Steyaert, Jan -- Dror, Ron O -- Kobilka, Brian K -- R01GM083118/GM/NIGMS NIH HHS/ -- R37 DA036246/DA/NIDA NIH HHS/ -- R37DA036246/DA/NIDA NIH HHS/ -- T32 GM008294/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Aug 20;524(7565):315-21. doi: 10.1038/nature14886. Epub 2015 Aug 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, California 94305, USA. ; Department of Computer Science, Stanford University, 318 Campus Drive, Stanford, California 94305, USA. ; Institute for Computational and Mathematical Engineering, Stanford University, 475 Via Ortega, Stanford, California 94305, USA. ; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. ; Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium. ; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA. ; Department of Chemistry and Pharmacy, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany. ; Institut de Genomique Fonctionnelle, CNRS UMR-5203 INSERM U1191, University of Montpellier, F-34000 Montpellier, France. ; Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK. ; Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26245379" target="_blank"〉PubMed〈/a〉

Description: The central dogma of gene expression (DNA to RNA to protein) is universal, but in different domains of life there are fundamental mechanistic differences within this pathway. For example, the canonical molecular signals used to initiate protein synthesis in bacteria and eukaryotes are mutually exclusive. However, the core structures and conformational dynamics of ribosomes that are responsible for the translation steps that take place after initiation are ancient and conserved across the domains of life. We wanted to explore whether an undiscovered RNA-based signal might be able to use these conserved features, bypassing mechanisms specific to each domain of life, and initiate protein synthesis in both bacteria and eukaryotes. Although structured internal ribosome entry site (IRES) RNAs can manipulate ribosomes to initiate translation in eukaryotic cells, an analogous RNA structure-based mechanism has not been observed in bacteria. Here we report our discovery that a eukaryotic viral IRES can initiate translation in live bacteria. We solved the crystal structure of this IRES bound to a bacterial ribosome to 3.8 A resolution, revealing that despite differences between bacterial and eukaryotic ribosomes this IRES binds directly to both and occupies the space normally used by transfer RNAs. Initiation in both bacteria and eukaryotes depends on the structure of the IRES RNA, but in bacteria this RNA uses a different mechanism that includes a form of ribosome repositioning after initial recruitment. This IRES RNA bridges billions of years of evolutionary divergence and provides an example of an RNA structure-based translation initiation signal capable of operating in two domains of life.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352134/" 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/PMC4352134/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Colussi, Timothy M -- Costantino, David A -- Zhu, Jianyu -- Donohue, John Paul -- Korostelev, Andrei A -- Jaafar, Zane A -- Plank, Terra-Dawn M -- Noller, Harry F -- Kieft, Jeffrey S -- GM-103105/GM/NIGMS NIH HHS/ -- GM-17129/GM/NIGMS NIH HHS/ -- GM-59140/GM/NIGMS NIH HHS/ -- GM-81346/GM/NIGMS NIH HHS/ -- GM-97333/GM/NIGMS NIH HHS/ -- R01 GM097333/GM/NIGMS NIH HHS/ -- R01 GM106105/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Mar 5;519(7541):110-3. doi: 10.1038/nature14219. Epub 2015 Feb 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, Colorado 80045, USA [2] Howard Hughes Medical Institute, University of Colorado Denver School of Medicine, Aurora, Colorado 80045, USA. ; Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, Sinsheimer Labs, University of California at Santa Cruz, Santa Cruz, California 95064, USA. ; Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, Colorado 80045, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25652826" target="_blank"〉PubMed〈/a〉

Description: Threats to genomic integrity arising from DNA damage are mitigated by DNA glycosylases, which initiate the base excision repair pathway by locating and excising aberrant nucleobases. How these enzymes find small modifications within the genome is a current area of intensive research. A hallmark of these and other DNA repair enzymes is their use of base flipping to sequester modified nucleotides from the DNA helix and into an active site pocket. Consequently, base flipping is generally regarded as an essential aspect of lesion recognition and a necessary precursor to base excision. Here we present the first, to our knowledge, DNA glycosylase mechanism that does not require base flipping for either binding or catalysis. Using the DNA glycosylase AlkD from Bacillus cereus, we crystallographically monitored excision of an alkylpurine substrate as a function of time, and reconstructed the steps along the reaction coordinate through structures representing substrate, intermediate and product complexes. Instead of directly interacting with the damaged nucleobase, AlkD recognizes aberrant base pairs through interactions with the phosphoribose backbone, while the lesion remains stacked in the DNA duplex. Quantum mechanical calculations revealed that these contacts include catalytic charge-dipole and CH-pi interactions that preferentially stabilize the transition state. We show in vitro and in vivo how this unique means of recognition and catalysis enables AlkD to repair large adducts formed by yatakemycin, a member of the duocarmycin family of antimicrobial natural products exploited in bacterial warfare and chemotherapeutic trials. Bulky adducts of this or any type are not excised by DNA glycosylases that use a traditional base-flipping mechanism. Hence, these findings represent a new model for DNA repair and provide insights into catalysis of base excision.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mullins, Elwood A -- Shi, Rongxin -- Parsons, Zachary D -- Yuen, Philip K -- David, Sheila S -- Igarashi, Yasuhiro -- Eichman, Brandt F -- R01 ES019625/ES/NIEHS NIH HHS/ -- R01CA067985/CA/NCI NIH HHS/ -- R01ES019625/ES/NIEHS NIH HHS/ -- S10RR026915/RR/NCRR NIH HHS/ -- T32 ES007028/ES/NIEHS NIH HHS/ -- T32ES07028/ES/NIEHS NIH HHS/ -- England -- Nature. 2015 Nov 12;527(7577):254-8. doi: 10.1038/nature15728. Epub 2015 Oct 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, USA. ; Department of Chemistry, University of California, Davis, California 95616, USA. ; Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26524531" target="_blank"〉PubMed〈/a〉

Description: Adiponectin stimulation of its receptors, AdipoR1 and AdipoR2, increases the activities of 5' AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR), respectively, thereby contributing to healthy longevity as key anti-diabetic molecules. AdipoR1 and AdipoR2 were predicted to contain seven transmembrane helices with the opposite topology to G-protein-coupled receptors. Here we report the crystal structures of human AdipoR1 and AdipoR2 at 2.9 and 2.4 A resolution, respectively, which represent a novel class of receptor structure. The seven-transmembrane helices, conformationally distinct from those of G-protein-coupled receptors, enclose a large cavity where three conserved histidine residues coordinate a zinc ion. The zinc-binding structure may have a role in the adiponectin-stimulated AMPK phosphorylation and UCP2 upregulation. Adiponectin may broadly interact with the extracellular face, rather than the carboxy-terminal tail, of the receptors. The present information will facilitate the understanding of novel structure-function relationships and the development and optimization of AdipoR agonists for the treatment of obesity-related diseases, such as type 2 diabetes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4477036/" 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/PMC4477036/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tanabe, Hiroaki -- Fujii, Yoshifumi -- Okada-Iwabu, Miki -- Iwabu, Masato -- Nakamura, Yoshihiro -- Hosaka, Toshiaki -- Motoyama, Kanna -- Ikeda, Mariko -- Wakiyama, Motoaki -- Terada, Takaho -- Ohsawa, Noboru -- Hato, Masakatsu -- Ogasawara, Satoshi -- Hino, Tomoya -- Murata, Takeshi -- Iwata, So -- Hirata, Kunio -- Kawano, Yoshiaki -- Yamamoto, Masaki -- Kimura-Someya, Tomomi -- Shirouzu, Mikako -- Yamauchi, Toshimasa -- Kadowaki, Takashi -- Yokoyama, Shigeyuki -- 062164/Z/00/Z/Wellcome Trust/United Kingdom -- 089809/Wellcome Trust/United Kingdom -- BB/G02325/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/G023425/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2015 Apr 16;520(7547):312-6. doi: 10.1038/nature14301. Epub 2015 Apr 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Department of Biophysics and Biochemistry and Laboratory of Structural Biology, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [3] Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [4] RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. ; 1] Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Integrated Molecular Science on Metabolic Diseases, 22nd Century Medical and Research Center, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. ; 1] Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Integrated Molecular Science on Metabolic Diseases, 22nd Century Medical and Research Center, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [3] PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [3] RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. ; RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. ; Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan. ; 1] Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan [2] JST, Research Acceleration Program, Membrane Protein Crystallography Project, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan [3] JST, Research Acceleration Program, Membrane Protein Crystallography Project, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan [4] Department of Chemistry, Graduate School of Science, Chiba University, Yayoi-cho, Inage, Chiba 263-8522, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan [3] JST, Research Acceleration Program, Membrane Protein Crystallography Project, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan [4] Division of Molecular Biosciences, Membrane Protein Crystallography Group, Imperial College, London SW7 2AZ, UK [5] Diamond Light Source, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire OX11 0DE, UK [6] RIKEN SPring-8 Center, Harima Institute, Kouto, Sayo, Hyogo 679-5148, Japan. ; RIKEN SPring-8 Center, Harima Institute, Kouto, Sayo, Hyogo 679-5148, Japan. ; 1] Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Integrated Molecular Science on Metabolic Diseases, 22nd Century Medical and Research Center, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [3] CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan. ; 1] RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan [2] Department of Biophysics and Biochemistry and Laboratory of Structural Biology, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [3] RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25855295" target="_blank"〉PubMed〈/a〉

Description: The E3 ubiquitin ligase PARKIN (encoded by PARK2) and the protein kinase PINK1 (encoded by PARK6) are mutated in autosomal-recessive juvenile Parkinsonism (AR-JP) and work together in the disposal of damaged mitochondria by mitophagy. PINK1 is stabilized on the outside of depolarized mitochondria and phosphorylates polyubiquitin as well as the PARKIN ubiquitin-like (Ubl) domain. These phosphorylation events lead to PARKIN recruitment to mitochondria, and activation by an unknown allosteric mechanism. Here we present the crystal structure of Pediculus humanus PARKIN in complex with Ser65-phosphorylated ubiquitin (phosphoUb), revealing the molecular basis for PARKIN recruitment and activation. The phosphoUb binding site on PARKIN comprises a conserved phosphate pocket and harbours residues mutated in patients with AR-JP. PhosphoUb binding leads to straightening of a helix in the RING1 domain, and the resulting conformational changes release the Ubl domain from the PARKIN core; this activates PARKIN. Moreover, phosphoUb-mediated Ubl release enhances Ubl phosphorylation by PINK1, leading to conformational changes within the Ubl domain and stabilization of an open, active conformation of PARKIN. We redefine the role of the Ubl domain not only as an inhibitory but also as an activating element that is restrained in inactive PARKIN and released by phosphoUb. Our work opens up new avenues to identify small-molecule PARKIN activators.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wauer, Tobias -- Simicek, Michal -- Schubert, Alexander -- Komander, David -- U105192732/Medical Research Council/United Kingdom -- England -- Nature. 2015 Aug 20;524(7565):370-4. doi: 10.1038/nature14879. Epub 2015 Jul 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26161729" target="_blank"〉PubMed〈/a〉

Description: The six-electron reduction of sulfite to sulfide is the pivot point of the biogeochemical cycle of the element sulfur. The octahaem cytochrome c MccA (also known as SirA) catalyses this reaction for dissimilatory sulfite utilization by various bacteria. It is distinct from known sulfite reductases because it has a substantially higher catalytic activity and a relatively low reactivity towards nitrite. The mechanistic reasons for the increased efficiency of MccA remain to be elucidated. Here we show that anoxically purified MccA exhibited a 2- to 5.5-fold higher specific sulfite reductase activity than the enzyme isolated under oxic conditions. We determined the three-dimensional structure of MccA to 2.2 A resolution by single-wavelength anomalous dispersion. We find a homotrimer with an unprecedented fold and haem arrangement, as well as a haem bound to a CX15CH motif. The heterobimetallic active-site haem 2 has a Cu(I) ion juxtaposed to a haem c at a Fe-Cu distance of 4.4 A. While the combination of metals is reminiscent of respiratory haem-copper oxidases, the oxidation-labile Cu(I) centre of MccA did not seem to undergo a redox transition during catalysis. Intact MccA tightly bound SO2 at haem 2, a dehydration product of the substrate sulfite that was partially turned over due to photoreduction by X-ray irradiation, yielding the reaction intermediate SO. Our data show the biometal copper in a new context and function and provide a chemical rationale for the comparatively high catalytic activity of MccA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hermann, Bianca -- Kern, Melanie -- La Pietra, Luigi -- Simon, Jorg -- Einsle, Oliver -- England -- Nature. 2015 Apr 30;520(7549):706-9. doi: 10.1038/nature14109. Epub 2015 Feb 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lehrstuhl Biochemie, Institut fur Biochemie, Albert-Ludwigs-Universitat Freiburg, Albertstrasse 21, 79104 Freiburg, Germany. ; Microbial Energy Conversion &Biotechnology, Department of Biology, Technische Universitat Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany. ; 1] Lehrstuhl Biochemie, Institut fur Biochemie, Albert-Ludwigs-Universitat Freiburg, Albertstrasse 21, 79104 Freiburg, Germany [2] BIOSS Centre for Biological Signalling Studies, Schanzlestrasse 1, 79104 Freiburg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25642962" target="_blank"〉PubMed〈/a〉

Description: Biomolecular self-assemblies are of great interest to nanotechnologists because of their functional versatility and their biocompatibility. Over the past decade, sophisticated single-component nanostructures composed exclusively of nucleic acids, peptides and proteins have been reported, and these nanostructures have been used in a wide range of applications, from drug delivery to molecular computing. Despite these successes, the development of hybrid co-assemblies of nucleic acids and proteins has remained elusive. Here we use computational protein design to create a protein-DNA co-assembling nanomaterial whose assembly is driven via non-covalent interactions. To achieve this, a homodimerization interface is engineered onto the Drosophila Engrailed homeodomain (ENH), allowing the dimerized protein complex to bind to two double-stranded DNA (dsDNA) molecules. By varying the arrangement of protein-binding sites on the dsDNA, an irregular bulk nanoparticle or a nanowire with single-molecule width can be spontaneously formed by mixing the protein and dsDNA building blocks. We characterize the protein-DNA nanowire using fluorescence microscopy, atomic force microscopy and X-ray crystallography, confirming that the nanowire is formed via the proposed mechanism. This work lays the foundation for the development of new classes of protein-DNA hybrid materials. Further applications can be explored by incorporating DNA origami, DNA aptamers and/or peptide epitopes into the protein-DNA framework presented here.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mou, Yun -- Yu, Jiun-Yann -- Wannier, Timothy M -- Guo, Chin-Lin -- Mayo, Stephen L -- England -- Nature. 2015 Sep 10;525(7568):230-3. doi: 10.1038/nature14874. Epub 2015 Sep 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA. ; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA. ; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26331548" target="_blank"〉PubMed〈/a〉

Description: Phytosulfokine (PSK) is a disulfated pentapeptide that has a ubiquitous role in plant growth and development. PSK is perceived by its receptor PSKR, a leucine-rich repeat receptor kinase (LRR-RK). The mechanisms underlying the recognition of PSK, the activation of PSKR and the identity of the components downstream of the initial binding remain elusive. Here we report the crystal structures of the extracellular LRR domain of PSKR in free, PSK- and co-receptor-bound forms. The structures reveal that PSK interacts mainly with a beta-strand from the island domain of PSKR, forming an anti-beta-sheet. The two sulfate moieties of PSK interact directly with PSKR, sensitizing PSKR recognition of PSK. Supported by biochemical, structural and genetic evidence, PSK binding enhances PSKR heterodimerization with the somatic embryogenesis receptor-like kinases (SERKs). However, PSK is not directly involved in PSKR-SERK interaction but stabilizes PSKR island domain for recruitment of a SERK. Our data reveal the structural basis for PSKR recognition of PSK and allosteric activation of PSKR by PSK, opening up new avenues for the design of PSKR-specific small molecules.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Jizong -- Li, Hongju -- Han, Zhifu -- Zhang, Heqiao -- Wang, Tong -- Lin, Guangzhong -- Chang, Junbiao -- Yang, Weicai -- Chai, Jijie -- England -- Nature. 2015 Sep 10;525(7568):265-8. doi: 10.1038/nature14858. Epub 2015 Aug 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China. ; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China. ; School of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26308901" target="_blank"〉PubMed〈/a〉

Description: DNA methylation at selective cytosine residues (5-methylcytosine (5mC)) and their removal by TET-mediated DNA demethylation are critical for setting up pluripotent states in early embryonic development. TET enzymes successively convert 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC), with 5fC and 5caC subject to removal by thymine DNA glycosylase (TDG) in conjunction with base excision repair. Early reports indicate that 5fC and 5caC could be stably detected on enhancers, promoters and gene bodies, with distinct effects on gene expression, but the mechanisms have remained elusive. Here we determined the X-ray crystal structure of yeast elongating RNA polymerase II (Pol II) in complex with a DNA template containing oxidized 5mCs, revealing specific hydrogen bonds between the 5-carboxyl group of 5caC and the conserved epi-DNA recognition loop in the polymerase. This causes a positional shift for incoming nucleoside 5'-triphosphate (NTP), thus compromising nucleotide addition. To test the implication of this structural insight in vivo, we determined the global effect of increased 5fC/5caC levels on transcription, finding that such DNA modifications indeed retarded Pol II elongation on gene bodies. These results demonstrate the functional impact of oxidized 5mCs on gene expression and suggest a novel role for Pol II as a specific and direct epigenetic sensor during transcription elongation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521995/" 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/PMC4521995/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Lanfeng -- Zhou, Yu -- Xu, Liang -- Xiao, Rui -- Lu, Xingyu -- Chen, Liang -- Chong, Jenny -- Li, Hairi -- He, Chuan -- Fu, Xiang-Dong -- Wang, Dong -- GM052872/GM/NIGMS NIH HHS/ -- GM102362/GM/NIGMS NIH HHS/ -- HG004659/HG/NHGRI NIH HHS/ -- HG006827/HG/NHGRI NIH HHS/ -- R01 GM052872/GM/NIGMS NIH HHS/ -- R01 GM102362/GM/NIGMS NIH HHS/ -- R01 HG004659/HG/NHGRI NIH HHS/ -- R01 HG006827/HG/NHGRI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Jul 30;523(7562):621-5. doi: 10.1038/nature14482. Epub 2015 Jun 29.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. ; Department of Cellular and Molecular Medicine, School of Medicine, The University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. ; Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, Howard Hughes Medical Institute, 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/26123024" target="_blank"〉PubMed〈/a〉

Description: In all domains of life, DNA synthesis occurs bidirectionally from replication origins. Despite variable rates of replication fork progression, fork convergence often occurs at specific sites. Escherichia coli sets a 'replication fork trap' that allows the first arriving fork to enter but not to leave the terminus region. The trap is set by oppositely oriented Tus-bound Ter sites that block forks on approach from only one direction. However, the efficiency of fork blockage by Tus-Ter does not exceed 50% in vivo despite its apparent ability to almost permanently arrest replication forks in vitro. Here we use data from single-molecule DNA replication assays and structural studies to show that both polarity and fork-arrest efficiency are determined by a competition between rates of Tus displacement and rearrangement of Tus-Ter interactions that leads to blockage of slower moving replisomes by two distinct mechanisms. To our knowledge this is the first example where intrinsic differences in rates of individual replisomes have different biological outcomes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Elshenawy, Mohamed M -- Jergic, Slobodan -- Xu, Zhi-Qiang -- Sobhy, Mohamed A -- Takahashi, Masateru -- Oakley, Aaron J -- Dixon, Nicholas E -- Hamdan, Samir M -- England -- Nature. 2015 Sep 17;525(7569):394-8. doi: 10.1038/nature14866. Epub 2015 Aug 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia. ; Centre for Medical &Molecular Bioscience, Illawarra Health &Medical Research Institute and University of Wollongong, New South Wales 2522, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26322585" target="_blank"〉PubMed〈/a〉

Description: Two-pore channels (TPCs) contain two copies of a Shaker-like six-transmembrane (6-TM) domain in each subunit and are ubiquitously expressed in both animals and plants as organellar cation channels. Here we present the crystal structure of a vacuolar two-pore channel from Arabidopsis thaliana, AtTPC1, which functions as a homodimer. AtTPC1 activation requires both voltage and cytosolic Ca(2+). Ca(2+) binding to the cytosolic EF-hand domain triggers conformational changes coupled to the pair of pore-lining inner helices from the first 6-TM domains, whereas membrane potential only activates the second voltage-sensing domain, the conformational changes of which are coupled to the pair of inner helices from the second 6-TM domains. Luminal Ca(2+) or Ba(2+) can modulate voltage activation by stabilizing the second voltage-sensing domain in the resting state and shift voltage activation towards more positive potentials. Our Ba(2+)-bound AtTPC1 structure reveals a voltage sensor in the resting state, providing hitherto unseen structural insight into the general voltage-gating mechanism among voltage-gated channels.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4841471/" 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/PMC4841471/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guo, Jiangtao -- Zeng, Weizhong -- Chen, Qingfeng -- Lee, Changkeun -- Chen, Liping -- Yang, Yi -- Cang, Chunlei -- Ren, Dejian -- Jiang, Youxing -- GM079179/GM/NIGMS NIH HHS/ -- NS055293/NS/NINDS NIH HHS/ -- NS074257/NS/NINDS NIH HHS/ -- R01 GM079179/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2016 Mar 10;531(7593):196-201. doi: 10.1038/nature16446. Epub 2015 Dec 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA. ; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA. ; Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26689363" target="_blank"〉PubMed〈/a〉

Description: Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with centromeric parC plasmid DNA, while facilitating the addition of subunits to ParM filaments. Growing ParMRC spindles push sister plasmids to the cell poles. Here, using modern electron cryomicroscopy methods, we investigate the structures and arrangements of ParM filaments in vitro and in cells, revealing at near-atomic resolution how subunits and filaments come together to produce the simplest known mitotic machinery. To understand the mechanism of dynamic instability, we determine structures of ParM filaments in different nucleotide states. The structure of filaments bound to the ATP analogue AMPPNP is determined at 4.3 A resolution and refined. The ParM filament structure shows strong longitudinal interfaces and weaker lateral interactions. Also using electron cryomicroscopy, we reconstruct ParM doublets forming antiparallel spindles. Finally, with whole-cell electron cryotomography, we show that doublets are abundant in bacterial cells containing low-copy-number plasmids with the ParMRC locus, leading to an asynchronous model of R1 plasmid segregation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4493928/" 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/PMC4493928/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bharat, Tanmay A M -- Murshudov, Garib N -- Sachse, Carsten -- Lowe, Jan -- 095514/Wellcome Trust/United Kingdom -- 095514/Z/11/Z/Wellcome Trust/United Kingdom -- MC-UP-A025-1012/Medical Research Council/United Kingdom -- MC_U105184326/Medical Research Council/United Kingdom -- U105184326/Medical Research Council/United Kingdom -- England -- Nature. 2015 Jul 2;523(7558):106-10. doi: 10.1038/nature14356. Epub 2015 Apr 27.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. ; Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg 69117, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25915019" target="_blank"〉PubMed〈/a〉

Description: G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a approximately 20 degrees rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521999/" 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/PMC4521999/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kang, Yanyong -- Zhou, X Edward -- Gao, Xiang -- He, Yuanzheng -- Liu, Wei -- Ishchenko, Andrii -- Barty, Anton -- White, Thomas A -- Yefanov, Oleksandr -- Han, Gye Won -- Xu, Qingping -- de Waal, Parker W -- Ke, Jiyuan -- Tan, M H Eileen -- Zhang, Chenghai -- Moeller, Arne -- West, Graham M -- Pascal, Bruce D -- Van Eps, Ned -- Caro, Lydia N -- Vishnivetskiy, Sergey A -- Lee, Regina J -- Suino-Powell, Kelly M -- Gu, Xin -- Pal, Kuntal -- Ma, Jinming -- Zhi, Xiaoyong -- Boutet, Sebastien -- Williams, Garth J -- Messerschmidt, Marc -- Gati, Cornelius -- Zatsepin, Nadia A -- Wang, Dingjie -- James, Daniel -- Basu, Shibom -- Roy-Chowdhury, Shatabdi -- Conrad, Chelsie E -- Coe, Jesse -- Liu, Haiguang -- Lisova, Stella -- Kupitz, Christopher -- Grotjohann, Ingo -- Fromme, Raimund -- Jiang, Yi -- Tan, Minjia -- Yang, Huaiyu -- Li, Jun -- Wang, Meitian -- Zheng, Zhong -- Li, Dianfan -- Howe, Nicole -- Zhao, Yingming -- Standfuss, Jorg -- Diederichs, Kay -- Dong, Yuhui -- Potter, Clinton S -- Carragher, Bridget -- Caffrey, Martin -- Jiang, Hualiang -- Chapman, Henry N -- Spence, John C H -- Fromme, Petra -- Weierstall, Uwe -- Ernst, Oliver P -- Katritch, Vsevolod -- Gurevich, Vsevolod V -- Griffin, Patrick R -- Hubbell, Wayne L -- Stevens, Raymond C -- Cherezov, Vadim -- Melcher, Karsten -- Xu, H Eric -- DK071662/DK/NIDDK NIH HHS/ -- EY005216/EY/NEI NIH HHS/ -- EY011500/EY/NEI NIH HHS/ -- GM073197/GM/NIGMS NIH HHS/ -- GM077561/GM/NIGMS NIH HHS/ -- GM095583/GM/NIGMS NIH HHS/ -- GM097463/GM/NIGMS NIH HHS/ -- GM102545/GM/NIGMS NIH HHS/ -- GM103310/GM/NIGMS NIH HHS/ -- GM104212/GM/NIGMS NIH HHS/ -- GM108635/GM/NIGMS NIH HHS/ -- P30EY000331/EY/NEI NIH HHS/ -- P41 GM103310/GM/NIGMS NIH HHS/ -- P41GM103393/GM/NIGMS NIH HHS/ -- P41RR001209/RR/NCRR NIH HHS/ -- P50 GM073197/GM/NIGMS NIH HHS/ -- P50 GM073210/GM/NIGMS NIH HHS/ -- R01 DK066202/DK/NIDDK NIH HHS/ -- R01 DK071662/DK/NIDDK NIH HHS/ -- R01 EY011500/EY/NEI NIH HHS/ -- R01 GM087413/GM/NIGMS NIH HHS/ -- R01 GM109955/GM/NIGMS NIH HHS/ -- S10 RR027270/RR/NCRR NIH HHS/ -- U54 GM094586/GM/NIGMS NIH HHS/ -- U54 GM094599/GM/NIGMS NIH HHS/ -- U54 GM094618/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Jul 30;523(7562):561-7. doi: 10.1038/nature14656. Epub 2015 Jul 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA. ; Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA. ; Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA. ; Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany. ; Joint Center for Structural Genomics, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; 1] Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA [2] Department of Obstetrics &Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. ; The National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, New York 10027, USA. ; Department of Molecular Therapeutics, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA. ; Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA. ; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada. ; Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA. ; Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; 1] Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA [2] BioXFEL, NSF Science and Technology Center, 700 Ellicott Street, Buffalo, New York 14203, USA. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Department of Physics, Arizona State University, Tempe, Arizona 85287, USA. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Beijing Computational Science Research Center, Haidian District, Beijing 10084, China. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA. ; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. ; Department of Obstetrics &Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. ; Swiss Light Source at Paul Scherrer Institute, CH-5232 Villigen, Switzerland. ; Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA. ; School of Medicine and School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland. ; 1] BioXFEL, NSF Science and Technology Center, 700 Ellicott Street, Buffalo, New York 14203, USA [2] Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637, USA. ; Laboratory of Biomolecular Research at Paul Scherrer Institute, CH-5232 Villigen, Switzerland. ; Department of Biology, Universitat Konstanz, 78457 Konstanz, Germany. ; Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. ; 1] Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany [2] Centre for Ultrafast Imaging, 22761 Hamburg, Germany. ; 1] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada. ; 1] Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA [2] Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA [3] iHuman Institute, ShanghaiTech University, 2F Building 6, 99 Haike Road, Pudong New District, Shanghai 201210, China. ; 1] Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA [2] VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26200343" target="_blank"〉PubMed〈/a〉

Description: Na(+)/Cl(-)-coupled biogenic amine transporters are the primary targets of therapeutic and abused drugs, ranging from antidepressants to the psychostimulants cocaine and amphetamines, and to their cognate substrates. Here we determine X-ray crystal structures of the Drosophila melanogaster dopamine transporter (dDAT) bound to its substrate dopamine, a substrate analogue 3,4-dichlorophenethylamine, the psychostimulants d-amphetamine and methamphetamine, or to cocaine and cocaine analogues. All ligands bind to the central binding site, located approximately halfway across the membrane bilayer, in close proximity to bound sodium and chloride ions. The central binding site recognizes three chemically distinct classes of ligands via conformational changes that accommodate varying sizes and shapes, thus illustrating molecular principles that distinguish substrates from inhibitors in biogenic amine transporters.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4469479/" 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/PMC4469479/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Kevin H -- Penmatsa, Aravind -- Gouaux, Eric -- F32 MH093120/MH/NIMH NIH HHS/ -- P50 DA018165/DA/NIDA NIH HHS/ -- P50DA018165/DA/NIDA NIH HHS/ -- R37 MH070039/MH/NIMH NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 May 21;521(7552):322-7. doi: 10.1038/nature14431. Epub 2015 May 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute, Oregon Health &Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA. ; 1] Vollum Institute, Oregon Health &Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA [2] Howard Hughes Medical Institute, Oregon Health &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/25970245" target="_blank"〉PubMed〈/a〉

Description: Dengue disease is caused by four different flavivirus serotypes, which infect 390 million people yearly with 25% symptomatic cases and for which no licensed vaccine is available. Recent phase III vaccine trials showed partial protection, and in particular no protection for dengue virus serotype 2 (refs 3, 4). Structural studies so far have characterized only epitopes recognized by serotype-specific human antibodies. We recently isolated human antibodies potently neutralizing all four dengue virus serotypes. Here we describe the X-ray structures of four of these broadly neutralizing antibodies in complex with the envelope glycoprotein E from dengue virus serotype 2, revealing that the recognition determinants are at a serotype-invariant site at the E-dimer interface, including the exposed main chain of the E fusion loop and the two conserved glycan chains. This 'E-dimer-dependent epitope' is also the binding site for the viral glycoprotein prM during virus maturation in the secretory pathway of the infected cell, explaining its conservation across serotypes and highlighting an Achilles' heel of the virus with respect to antibody neutralization. These findings will be instrumental for devising novel immunogens to protect simultaneously against all four serotypes of dengue virus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rouvinski, Alexander -- Guardado-Calvo, Pablo -- Barba-Spaeth, Giovanna -- Duquerroy, Stephane -- Vaney, Marie-Christine -- Kikuti, Carlos M -- Navarro Sanchez, M Erika -- Dejnirattisai, Wanwisa -- Wongwiwat, Wiyada -- Haouz, Ahmed -- Girard-Blanc, Christine -- Petres, Stephane -- Shepard, William E -- Despres, Philippe -- Arenzana-Seisdedos, Fernando -- Dussart, Philippe -- Mongkolsapaya, Juthathip -- Screaton, Gavin R -- Rey, Felix A -- 095541/Wellcome Trust/United Kingdom -- Medical Research Council/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2015 Apr 2;520(7545):109-13. doi: 10.1038/nature14130. Epub 2015 Jan 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Institut Pasteur, Departement de Virologie, Unite de Virologie Structurale, 75724 Paris Cedex 15, France [2] CNRS UMR 3569 Virologie, 75724 Paris Cedex 15, France. ; 1] Institut Pasteur, Departement de Virologie, Unite de Virologie Structurale, 75724 Paris Cedex 15, France [2] CNRS UMR 3569 Virologie, 75724 Paris Cedex 15, France [3] Universite Paris-Sud, Faculte des Sciences, 91405 Orsay, France. ; Division of Immunology and Inflammation, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London W12 0NN, UK. ; Institut Pasteur, Proteopole, CNRS UMR 3528, 75724 Paris Cedex 15, France. ; Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, BP48, 91192 Gif-sur-Yvette, France. ; Institut Pasteur, Departement de Virologie, Unite des Interactions Moleculaires Flavivirus-Hotes, 75724 Paris Cedex 15, France. ; Institut Pasteur, Departement de Virologie, Unite de Pathogenie Virale, INSERM U1108, 75724 Paris Cedex 15, France. ; Institut Pasteur de Guyane, BP 6010, 97306 Cayenne, French Guiana. ; 1] Division of Immunology and Inflammation, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London W12 0NN, UK [2] Dengue Hemorrhagic Fever Research Unit, Office for Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. ; 1] Institut Pasteur, Departement de Virologie, Unite de Virologie Structurale, 75724 Paris Cedex 15, France [2] CNRS UMR 3569 Virologie, 75724 Paris Cedex 15, France [3] Institut Pasteur, Proteopole, CNRS UMR 3528, 75724 Paris Cedex 15, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25581790" target="_blank"〉PubMed〈/a〉

Description: Bacteria and archaea generate adaptive immunity against phages and plasmids by integrating foreign DNA of specific 30-40-base-pair lengths into clustered regularly interspaced short palindromic repeat (CRISPR) loci as spacer segments. The universally conserved Cas1-Cas2 integrase complex catalyses spacer acquisition using a direct nucleophilic integration mechanism similar to retroviral integrases and transposases. How the Cas1-Cas2 complex selects foreign DNA substrates for integration remains unknown. Here we present X-ray crystal structures of the Escherichia coli Cas1-Cas2 complex bound to cognate 33-nucleotide protospacer DNA substrates. The protein complex creates a curved binding surface spanning the length of the DNA and splays the ends of the protospacer to allow each terminal nucleophilic 3'-OH to enter a channel leading into the Cas1 active sites. Phosphodiester backbone interactions between the protospacer and the proteins explain the sequence-nonspecific substrate selection observed in vivo. Our results uncover the structural basis for foreign DNA capture and the mechanism by which Cas1-Cas2 functions as a molecular ruler to dictate the sequence architecture of CRISPR loci.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4662619/" 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/PMC4662619/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nunez, James K -- Harrington, Lucas B -- Kranzusch, Philip J -- Engelman, Alan N -- Doudna, Jennifer A -- AI070042/AI/NIAID NIH HHS/ -- R01 AI070042/AI/NIAID NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Nov 26;527(7579):535-8. doi: 10.1038/nature15760. Epub 2015 Oct 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA. ; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, California 94720, USA. ; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA. ; Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA. ; Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA. ; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. ; Innovative Genomics Initiative, University of California, Berkeley, Berkeley, California 94720, USA. ; Center for RNA Systems Biology, 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/26503043" target="_blank"〉PubMed〈/a〉

Description: Low-valent late transition-metal catalysis has become indispensable to chemical synthesis, but homogeneous high-valent transition-metal catalysis is underdeveloped, mainly owing to the reactivity of high-valent transition-metal complexes and the challenges associated with synthesizing them. Here we report a carbon-carbon bond cleavage at ambient conditions by a Au(i) complex that generates a stable Au(iii) cationic complex. In contrast to the well-established soft and carbophilic Au(i) catalyst, this Au(iii) complex exhibits hard, oxophilic Lewis acidity. For example, we observed catalytic activation of alpha,beta-unsaturated aldehydes towards selective conjugate additions as well as activation of an unsaturated aldehyde-allene for a [2 + 2] cycloaddition reaction. The origin of the regioselectivity and catalytic activity was elucidated by X-ray crystallographic analysis of an isolated Au(iii)-activated cinnamaldehyde intermediate. The concepts revealed suggest a strategy for accessing high-valent transition-metal catalysis from readily available precursors.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4304402/" 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/PMC4304402/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wu, Chung-Yeh -- Horibe, Takahiro -- Jacobsen, Christian Borch -- Toste, F Dean -- R01 GM073932/GM/NIGMS NIH HHS/ -- S10-RR027172/RR/NCRR NIH HHS/ -- England -- Nature. 2015 Jan 22;517(7535):449-54. doi: 10.1038/nature14104.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of California, Berkeley, California 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25612049" target="_blank"〉PubMed〈/a〉

Description: The hypoxia-inducible factors (HIFs) coordinate cellular adaptations to low oxygen stress by regulating transcriptional programs in erythropoiesis, angiogenesis and metabolism. These programs promote the growth and progression of many tumours, making HIFs attractive anticancer targets. Transcriptionally active HIFs consist of HIF-alpha and ARNT (also called HIF-1beta) subunits. Here we describe crystal structures for each of mouse HIF-2alpha-ARNT and HIF-1alpha-ARNT heterodimers in states that include bound small molecules and their hypoxia response element. A highly integrated quaternary architecture is shared by HIF-2alpha-ARNT and HIF-1alpha-ARNT, wherein ARNT spirals around the outside of each HIF-alpha subunit. Five distinct pockets are observed that permit small-molecule binding, including PAS domain encapsulated sites and an interfacial cavity formed through subunit heterodimerization. The DNA-reading head rotates, extends and cooperates with a distal PAS domain to bind hypoxia response elements. HIF-alpha mutations linked to human cancers map to sensitive sites that establish DNA binding and the stability of PAS domains and pockets.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wu, Dalei -- Potluri, Nalini -- Lu, Jingping -- Kim, Youngchang -- Rastinejad, Fraydoon -- England -- Nature. 2015 Aug 20;524(7565):303-8. doi: 10.1038/nature14883. Epub 2015 Aug 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Metabolic Disease Program, Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida 32827, USA. ; Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26245371" target="_blank"〉PubMed〈/a〉

Description: Initiation of cellular DNA replication is tightly controlled to sustain genomic integrity. In eukaryotes, the heterohexameric origin recognition complex (ORC) is essential for coordinating replication onset. Here we describe the crystal structure of Drosophila ORC at 3.5 A resolution, showing that the 270 kilodalton initiator core complex comprises a two-layered notched ring in which a collar of winged-helix domains from the Orc1-5 subunits sits atop a layer of AAA+ (ATPases associated with a variety of cellular activities) folds. Although canonical inter-AAA+ domain interactions exist between four of the six ORC subunits, unanticipated features are also evident. These include highly interdigitated domain-swapping interactions between the winged-helix folds and AAA+ modules of neighbouring protomers, and a quasi-spiral arrangement of DNA binding elements that circumnavigate an approximately 20 A wide channel in the centre of the complex. Comparative analyses indicate that ORC encircles DNA, using its winged-helix domain face to engage the mini-chromosome maintenance 2-7 (MCM2-7) complex during replicative helicase loading; however, an observed out-of-plane rotation of more than 90 degrees for the Orc1 AAA+ domain disrupts interactions with catalytic amino acids in Orc4, narrowing and sealing off entry into the central channel. Prima facie, our data indicate that Drosophila ORC can switch between active and autoinhibited conformations, suggesting a novel means for cell cycle and/or developmental control of ORC functions.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4368505/" 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/PMC4368505/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bleichert, Franziska -- Botchan, Michael R -- Berger, James M -- CA R37-30490/CA/NCI NIH HHS/ -- GM071747/GM/NIGMS NIH HHS/ -- R01 GM071747/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Mar 19;519(7543):321-6. doi: 10.1038/nature14239. Epub 2015 Mar 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA. ; Department of Molecular and Cell Biology, 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/25762138" target="_blank"〉PubMed〈/a〉

Description: The enzyme hydrogenase reversibly converts dihydrogen to protons and electrons at a metal catalyst. The location of the abundant hydrogens is of key importance for understanding structure and function of the protein. However, in protein X-ray crystallography the detection of hydrogen atoms is one of the major problems, since they display only weak contributions to diffraction and the quality of the single crystals is often insufficient to obtain sub-angstrom resolution. Here we report the crystal structure of a standard [NiFe] hydrogenase ( approximately 91.3 kDa molecular mass) at 0.89 A resolution. The strictly anoxically isolated hydrogenase has been obtained in a specific spectroscopic state, the active reduced Ni-R (subform Ni-R1) state. The high resolution, proper refinement strategy and careful modelling allow the positioning of a large part of the hydrogen atoms in the structure. This has led to the direct detection of the products of the heterolytic splitting of dihydrogen into a hydride (H(-)) bridging the Ni and Fe and a proton (H(+)) attached to the sulphur of a cysteine ligand. The Ni-H(-) and Fe-H(-) bond lengths are 1.58 A and 1.78A, respectively. Furthermore, we can assign the Fe-CO and Fe-CN(-) ligands at the active site, and can obtain the hydrogen-bond networks and the preferred proton transfer pathway in the hydrogenase. Our results demonstrate the precise comprehensive information available from ultra-high-resolution structures of proteins as an alternative to neutron diffraction and other methods such as NMR structural analysis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ogata, Hideaki -- Nishikawa, Koji -- Lubitz, Wolfgang -- England -- Nature. 2015 Apr 23;520(7548):571-4. doi: 10.1038/nature14110. Epub 2015 Jan 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mulheim an der Ruhr, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25624102" target="_blank"〉PubMed〈/a〉

Description: Innate immunity serves as the first line of defence against invading pathogens such as bacteria and viruses. Toll-like receptors (TLRs) are examples of innate immune receptors, which sense specific molecular patterns from pathogens and activate immune responses. TLR9 recognizes bacterial and viral DNA containing the cytosine-phosphate-guanine (CpG) dideoxynucleotide motif. The molecular basis by which CpG-containing DNA (CpG-DNA) elicits immunostimulatory activity via TLR9 remains to be elucidated. Here we show the crystal structures of three forms of TLR9: unliganded, bound to agonistic CpG-DNA, and bound to inhibitory DNA (iDNA). Agonistic-CpG-DNA-bound TLR9 formed a symmetric TLR9-CpG-DNA complex with 2:2 stoichiometry, whereas iDNA-bound TLR9 was a monomer. CpG-DNA was recognized by both protomers in the dimer, in particular by the amino-terminal fragment (LRRNT-LRR10) from one protomer and the carboxy-terminal fragment (LRR20-LRR22) from the other. The iDNA, which formed a stem-loop structure suitable for binding by intramolecular base pairing, bound to the concave surface from LRR2-LRR10. This structure serves as an important basis for improving our understanding of the functional mechanisms of TLR9.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ohto, Umeharu -- Shibata, Takuma -- Tanji, Hiromi -- Ishida, Hanako -- Krayukhina, Elena -- Uchiyama, Susumu -- Miyake, Kensuke -- Shimizu, Toshiyuki -- England -- Nature. 2015 Apr 30;520(7549):702-5. doi: 10.1038/nature14138. Epub 2015 Feb 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. ; 1] Division of Innate Immunity, Department of Microbiology and Immunology, Laboratory of Innate Immunity, Center for Experimental Medicine and Systems Biology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan [2] Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan. ; 1] Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan [2] U-Medico Corporation, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. ; Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. ; Division of Innate Immunity, Department of Microbiology and Immunology, Laboratory of Innate Immunity, Center for Experimental Medicine and Systems Biology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. ; 1] Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25686612" target="_blank"〉PubMed〈/a〉

Description: Many peroxy-containing secondary metabolites have been isolated and shown to provide beneficial effects to human health. Yet, the mechanisms of most endoperoxide biosyntheses are not well understood. Although endoperoxides have been suggested as key reaction intermediates in several cases, the only well-characterized endoperoxide biosynthetic enzyme is prostaglandin H synthase, a haem-containing enzyme. Fumitremorgin B endoperoxidase (FtmOx1) from Aspergillus fumigatus is the first reported alpha-ketoglutarate-dependent mononuclear non-haem iron enzyme that can catalyse an endoperoxide formation reaction. To elucidate the mechanistic details for this unique chemical transformation, we report the X-ray crystal structures of FtmOx1 and the binary complexes it forms with either the co-substrate (alpha-ketoglutarate) or the substrate (fumitremorgin B). Uniquely, after alpha-ketoglutarate has bound to the mononuclear iron centre in a bidentate fashion, the remaining open site for oxygen binding and activation is shielded from the substrate or the solvent by a tyrosine residue (Y224). Upon replacing Y224 with alanine or phenylalanine, the FtmOx1 catalysis diverts from endoperoxide formation to the more commonly observed hydroxylation. Subsequent characterizations by a combination of stopped-flow optical absorption spectroscopy and freeze-quench electron paramagnetic resonance spectroscopy support the presence of transient radical species in FtmOx1 catalysis. Our results help to unravel the novel mechanism for this endoperoxide formation reaction.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yan, Wupeng -- Song, Heng -- Song, Fuhang -- Guo, Yisong -- Wu, Cheng-Hsuan -- Sae Her, Ampon -- Pu, Yi -- Wang, Shu -- Naowarojna, Nathchar -- Weitz, Andrew -- Hendrich, Michael P -- Costello, Catherine E -- Zhang, Lixin -- Liu, Pinghua -- Zhang, Yan Jessie -- P41 GM104603/GM/NIGMS NIH HHS/ -- R01 GM077387/GM/NIGMS NIH HHS/ -- R01 GM093903/GM/NIGMS NIH HHS/ -- R01 GM104896/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Nov 26;527(7579):539-43. doi: 10.1038/nature15519. Epub 2015 Nov 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, USA. ; Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA. ; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. ; Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA. ; Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02118, USA. ; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26524521" target="_blank"〉PubMed〈/a〉

Description: A central question in protein evolution is the extent to which naturally occurring proteins sample the space of folded structures accessible to the polypeptide chain. Repeat proteins composed of multiple tandem copies of a modular structure unit are widespread in nature and have critical roles in molecular recognition, signalling, and other essential biological processes. Naturally occurring repeat proteins have been re-engineered for molecular recognition and modular scaffolding applications. Here we use computational protein design to investigate the space of folded structures that can be generated by tandem repeating a simple helix-loop-helix-loop structural motif. Eighty-three designs with sequences unrelated to known repeat proteins were experimentally characterized. Of these, 53 are monomeric and stable at 95 degrees C, and 43 have solution X-ray scattering spectra consistent with the design models. Crystal structures of 15 designs spanning a broad range of curvatures are in close agreement with the design models with root mean square deviations ranging from 0.7 to 2.5 A. Our results show that existing repeat proteins occupy only a small fraction of the possible repeat protein sequence and structure space and that it is possible to design novel repeat proteins with precisely specified geometries, opening up a wide array of new possibilities for biomolecular engineering.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brunette, T J -- Parmeggiani, Fabio -- Huang, Po-Ssu -- Bhabha, Gira -- Ekiert, Damian C -- Tsutakawa, Susan E -- Hura, Greg L -- Tainer, John A -- Baker, David -- GM105404/GM/NIGMS NIH HHS/ -- K99GM112982/GM/NIGMS NIH HHS/ -- R01 GM105404/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Dec 24;528(7583):580-4. doi: 10.1038/nature16162. Epub 2015 Dec 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA. ; Institute for Protein Design, University of Washington, Seattle, Washington 98195, USA. ; Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California 94158, USA. ; Department of Microbiology and Immunology, UCSF, San Francisco, California 94158, USA. ; Molecular Biophysics &Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. ; Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA. ; Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. ; Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26675729" target="_blank"〉PubMed〈/a〉

Description: Photoreceptor proteins enable organisms to sense and respond to light. The newly discovered CarH-type photoreceptors use a vitamin B12 derivative, adenosylcobalamin, as the light-sensing chromophore to mediate light-dependent gene regulation. Here we present crystal structures of Thermus thermophilus CarH in all three relevant states: in the dark, both free and bound to operator DNA, and after light exposure. These structures provide visualizations of how adenosylcobalamin mediates CarH tetramer formation in the dark, how this tetramer binds to the promoter -35 element to repress transcription, and how light exposure leads to a large-scale conformational change that activates transcription. In addition to the remarkable functional repurposing of adenosylcobalamin from an enzyme cofactor to a light sensor, we find that nature also repurposed two independent protein modules in assembling CarH. These results expand the biological role of vitamin B12 and provide fundamental insight into a new mode of light-dependent gene regulation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634937/" 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/PMC4634937/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jost, Marco -- Fernandez-Zapata, Jesus -- Polanco, Maria Carmen -- Ortiz-Guerrero, Juan Manuel -- Chen, Percival Yang-Ting -- Kang, Gyunghoon -- Padmanabhan, S -- Elias-Arnanz, Montserrat -- Drennan, Catherine L -- GM069857/GM/NIGMS NIH HHS/ -- P41 GM103393/GM/NIGMS NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- P41GM103393/GM/NIGMS NIH HHS/ -- P41GM103403/GM/NIGMS NIH HHS/ -- R01 GM069857/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Oct 22;526(7574):536-41. doi: 10.1038/nature14950. Epub 2015 Sep 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Instituto de Quimica Fisica "Rocasolano", Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain. ; Department of Genetics and Microbiology, Area of Genetics (Unidad Asociada al Instituto de Quimica Fisica "Rocasolano", Consejo Superior de Investigaciones Cientificas), Faculty of Biology, Universidad de Murcia, Murcia 30100, Spain. ; Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Howard Hughes Medical Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26416754" target="_blank"〉PubMed〈/a〉

Description: Glutamate transporters terminate neurotransmission by clearing synaptically released glutamate from the extracellular space, allowing repeated rounds of signalling and preventing glutamate-mediated excitotoxicity. Crystallographic studies of a glutamate transporter homologue from the archaeon Pyrococcus horikoshii, GltPh, showed that distinct transport domains translocate substrates into the cytoplasm by moving across the membrane within a central trimerization scaffold. Here we report direct observations of these 'elevator-like' transport domain motions in the context of reconstituted proteoliposomes and physiological ion gradients using single-molecule fluorescence resonance energy transfer (smFRET) imaging. We show that GltPh bearing two mutations introduced to impart characteristics of the human transporter exhibits markedly increased transport domain dynamics, which parallels an increased rate of substrate transport, thereby establishing a direct temporal relationship between transport domain motion and substrate uptake. Crystallographic and computational investigations corroborated these findings by revealing that the 'humanizing' mutations favour structurally 'unlocked' intermediate states in the transport cycle exhibiting increased solvent occupancy at the interface between the transport domain and the trimeric scaffold.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351760/" 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/PMC4351760/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Akyuz, Nurunisa -- Georgieva, Elka R -- Zhou, Zhou -- Stolzenberg, Sebastian -- Cuendet, Michel A -- Khelashvili, George -- Altman, Roger B -- Terry, Daniel S -- Freed, Jack H -- Weinstein, Harel -- Boudker, Olga -- Blanchard, Scott C -- 5U54GM087519/GM/NIGMS NIH HHS/ -- P01DA012408/DA/NIDA NIH HHS/ -- P41 GM103521/GM/NIGMS NIH HHS/ -- P41GM103521/GM/NIGMS NIH HHS/ -- R01 EB003150/EB/NIBIB NIH HHS/ -- R01 GM025862/GM/NIGMS NIH HHS/ -- R01 GM098859/GM/NIGMS NIH HHS/ -- R010EB003150/EB/NIBIB NIH HHS/ -- R01GM098859/GM/NIGMS NIH HHS/ -- R21MH099491/MH/NIMH NIH HHS/ -- R37 NS085318/NS/NINDS NIH HHS/ -- England -- Nature. 2015 Feb 5;518(7537):68-73. doi: 10.1038/nature14158.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Biophysics, Weill Cornell Medical College, Cornell University, 1300 York Avenue, New York, New York 10065, USA. ; 1] National Biomedical Center for Advanced ESR Technology, Cornell University, Ithaca, New York 14853, USA [2] Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA. ; 1] Department of Physiology and Biophysics, Weill Cornell Medical College, Cornell University, 1300 York Avenue, New York, New York 10065, USA [2] Swiss Institute of Bioinformatics, Quartier Sorge - Batiment Genopode, 1015 Lausanne, Switzerland. ; 1] Department of Physiology and Biophysics, Weill Cornell Medical College, Cornell University, 1300 York Avenue, New York, New York 10065, USA [2] HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, 1305 York Avenue, New York, New York 10065, USA. ; 1] Department of Physiology and Biophysics, Weill Cornell Medical College, Cornell University, 1300 York Avenue, New York, New York 10065, USA [2] Tri-Institutional Training Program in Chemical Biology, 445 East 69th Street, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25652997" target="_blank"〉PubMed〈/a〉

Description: Eukaryotes rely on efficient distribution of energy and carbon skeletons between organs in the form of sugars. Glucose in animals and sucrose in plants serve as the dominant distribution forms. Cellular sugar uptake and release require vesicular and/or plasma membrane transport proteins. Humans and plants use proteins from three superfamilies for sugar translocation: the major facilitator superfamily (MFS), the sodium solute symporter family (SSF; only in the animal kingdom), and SWEETs. SWEETs carry mono- and disaccharides across vacuolar or plasma membranes. Plant SWEETs play key roles in sugar translocation between compartments, cells, and organs, notably in nectar secretion, phloem loading for long distance translocation, pollen nutrition, and seed filling. Plant SWEETs cause pathogen susceptibility possibly by sugar leakage from infected cells. The vacuolar Arabidopsis thaliana AtSWEET2 sequesters sugars in root vacuoles; loss-of-function mutants show increased susceptibility to Pythium infection. Here we show that its orthologue, the vacuolar glucose transporter OsSWEET2b from rice (Oryza sativa), consists of an asymmetrical pair of triple-helix bundles, connected by an inversion linker transmembrane helix (TM4) to create the translocation pathway. Structural and biochemical analyses show OsSWEET2b in an apparent inward (cytosolic) open state forming homomeric trimers. TM4 tightly interacts with the first triple-helix bundle within a protomer and mediates key contacts among protomers. Structure-guided mutagenesis of the close paralogue SWEET1 from Arabidopsis identified key residues in substrate translocation and protomer crosstalk. Insights into the structure-function relationship of SWEETs are valuable for understanding the transport mechanism of eukaryotic SWEETs and may be useful for engineering sugar flux.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734654/" 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/PMC4734654/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tao, Yuyong -- Cheung, Lily S -- Li, Shuo -- Eom, Joon-Seob -- Chen, Li-Qing -- Xu, Yan -- Perry, Kay -- Frommer, Wolf B -- Feng, Liang -- P41 GM103403/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Nov 12;527(7577):259-63. doi: 10.1038/nature15391. Epub 2015 Oct 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Physiology, 279 Campus Drive, Stanford University School of Medicine, Stanford, California 94305, USA. ; Carnegie Institution for Science, Department of Plant Biology, 260 Panama Street, Stanford, California 94305, USA. ; Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610014, China. ; NE-CAT and Dep. of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26479032" target="_blank"〉PubMed〈/a〉

Description: Bacteria share their ecological niches with other microbes. The bacterial type VI secretion system is one of the key players in microbial competition, as well as being an important virulence determinant during bacterial infections. It assembles a nano-crossbow-like structure in the cytoplasm of the attacker cell that propels an arrow made of a haemolysin co-regulated protein (Hcp) tube and a valine-glycine repeat protein G (VgrG) spike and punctures the prey's cell wall. The nano-crossbow is stably anchored to the cell envelope of the attacker by a membrane core complex. Here we show that this complex is assembled by the sequential addition of three type VI subunits (Tss)-TssJ, TssM and TssL-and present a structure of the fully assembled complex at 11.6 A resolution, determined by negative-stain electron microscopy. With overall C5 symmetry, this 1.7-megadalton complex comprises a large base in the cytoplasm. It extends in the periplasm via ten arches to form a double-ring structure containing the carboxy-terminal domain of TssM (TssMct) and TssJ that is anchored in the outer membrane. The crystal structure of the TssMct-TssJ complex coupled to whole-cell accessibility studies suggest that large conformational changes induce transient pore formation in the outer membrane, allowing passage of the attacking Hcp tube/VgrG spike.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Durand, Eric -- Nguyen, Van Son -- Zoued, Abdelrahim -- Logger, Laureen -- Pehau-Arnaudet, Gerard -- Aschtgen, Marie-Stephanie -- Spinelli, Silvia -- Desmyter, Aline -- Bardiaux, Benjamin -- Dujeancourt, Annick -- Roussel, Alain -- Cambillau, Christian -- Cascales, Eric -- Fronzes, Remi -- England -- Nature. 2015 Jul 30;523(7562):555-60. doi: 10.1038/nature14667. Epub 2015 Jul 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Laboratoire d'Ingenierie des Systemes Macromoleculaires, Aix-Marseille Universite - CNRS, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France [2] Architecture et Fonction des Macromolecules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France [3] G5 Biologie structurale de la secretion bacterienne, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France [4] UMR 3528, CNRS, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France [5] AFMB, Aix-Marseille Universite, IHU Mediterranee Infection, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France. ; 1] Architecture et Fonction des Macromolecules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France [2] AFMB, Aix-Marseille Universite, IHU Mediterranee Infection, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France. ; Laboratoire d'Ingenierie des Systemes Macromoleculaires, Aix-Marseille Universite - CNRS, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. ; UMR 3528, CNRS, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France. ; 1] UMR 3528, CNRS, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France [2] Unite de Bioinformatique Structurale, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France. ; 1] G5 Biologie structurale de la secretion bacterienne, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France [2] UMR 3528, CNRS, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26200339" target="_blank"〉PubMed〈/a〉

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〉

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〉

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〉

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〉

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〉

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〉

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〉

Description: The self-assembly of proteins into highly ordered nanoscale architectures is a hallmark of biological systems. The sophisticated functions of these molecular machines have inspired the development of methods to engineer self-assembling protein nanostructures; however, the design of multi-component protein nanomaterials with high accuracy remains an outstanding challenge. Here we report a computational method for designing protein nanomaterials in which multiple copies of two distinct subunits co-assemble into a specific architecture. We use the method to design five 24-subunit cage-like protein nanomaterials in two distinct symmetric architectures and experimentally demonstrate that their structures are in close agreement with the computational design models. The accuracy of the method and the number and variety of two-component materials that it makes accessible suggest a route to the construction of functional protein nanomaterials tailored to specific applications.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4137318/" 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/PMC4137318/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉King, Neil P -- Bale, Jacob B -- Sheffler, William -- McNamara, Dan E -- Gonen, Shane -- Gonen, Tamir -- Yeates, Todd O -- Baker, David -- T32 GM067555/GM/NIGMS NIH HHS/ -- T32GM067555/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Jun 5;510(7503):103-8. doi: 10.1038/nature13404. Epub 2014 May 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA [2] Institute for Protein Design, University of Washington, Seattle, Washington 98195, USA [3]. ; 1] Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA [2] Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington 98195, USA [3]. ; 1] Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA [2]. ; UCLA Department of Chemistry and Biochemistry, Los Angeles, California 90095, USA. ; 1] Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA [2] Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA. ; Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, Virginia 20147, USA. ; 1] UCLA Department of Chemistry and Biochemistry, Los Angeles, California 90095, USA [2] UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, California 90095, USA [3] UCLA Molecular Biology Institute, Los Angeles, California 90095, USA. ; 1] Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA [2] Institute for Protein Design, University of Washington, Seattle, Washington 98195, USA [3] Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24870237" target="_blank"〉PubMed〈/a〉

Description: In bacterial cells, processing of double-stranded DNA breaks for repair by homologous recombination is dependent upon the recombination hotspot sequence chi (Chi) and is catalysed by either an AddAB- or RecBCD-type helicase-nuclease (reviewed in refs 3, 4). These enzyme complexes unwind and digest the DNA duplex from the broken end until they encounter a chi sequence, whereupon they produce a 3' single-stranded DNA tail onto which they initiate loading of the RecA protein. Consequently, regulation of the AddAB/RecBCD complex by chi is a key control point in DNA repair and other processes involving genetic recombination. Here we report crystal structures of Bacillus subtilis AddAB in complex with different chi-containing DNA substrates either with or without a non-hydrolysable ATP analogue. Comparison of these structures suggests a mechanism for DNA translocation and unwinding, suggests how the enzyme binds specifically to chi sequences, and explains how chi recognition leads to the arrest of AddAB (and RecBCD) translocation that is observed in single-molecule experiments.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3991583/" 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/PMC3991583/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Krajewski, Wojciech W -- Fu, Xin -- Wilkinson, Martin -- Cronin, Nora B -- Dillingham, Mark S -- Wigley, Dale B -- 100401/Wellcome Trust/United Kingdom -- 12799/Cancer Research UK/United Kingdom -- A12799/Cancer Research UK/United Kingdom -- Cancer Research UK/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2014 Apr 17;508(7496):416-9. doi: 10.1038/nature13037. Epub 2014 Mar 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK [2] CRT Discovery Laboratories, Department of Biological Sciences, Birkbeck, University of London, London WC1E 7HX, UK. ; Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK. ; School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24670664" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Whorton, Matt -- England -- Nature. 2014 Dec 11;516(7530):176-8. doi: 10.1038/nature13944. Epub 2014 Nov 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239-3098, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25383534" target="_blank"〉PubMed〈/a〉

Description: NADH oxidation in the respiratory chain is coupled to ion translocation across the membrane to build up an electrochemical gradient. The sodium-translocating NADH:quinone oxidoreductase (Na(+)-NQR), a membrane protein complex widespread among pathogenic bacteria, consists of six subunits, NqrA, B, C, D, E and F. To our knowledge, no structural information on the Na(+)-NQR complex has been available until now. Here we present the crystal structure of the Na(+)-NQR complex at 3.5 A resolution. The arrangement of cofactors both at the cytoplasmic and the periplasmic side of the complex, together with a hitherto unknown iron centre in the midst of the membrane-embedded part, reveals an electron transfer pathway from the NADH-oxidizing cytoplasmic NqrF subunit across the membrane to the periplasmic NqrC, and back to the quinone reduction site on NqrA located in the cytoplasm. A sodium channel was localized in subunit NqrB, which represents the largest membrane subunit of the Na(+)-NQR and is structurally related to urea and ammonia transporters. On the basis of the structure we propose a mechanism of redox-driven Na(+) translocation where the change in redox state of the flavin mononucleotide cofactor in NqrB triggers the transport of Na(+) through the observed channel.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Steuber, Julia -- Vohl, Georg -- Casutt, Marco S -- Vorburger, Thomas -- Diederichs, Kay -- Fritz, Gunter -- England -- Nature. 2014 Dec 4;516(7529):62-7. doi: 10.1038/nature14003.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, Garbenstrasse 30, University of Hohenheim, 70599 Stuttgart, Germany. ; 1] Institute for Neuropathology, University of Freiburg, Breisacher Strasse 64, 79106 Freiburg, Germany [2] Hermann-Staudinger-Graduate school, University of Freiburg, Hebelstrasse 27, 79104 Freiburg, Germany. ; Institute for Neuropathology, University of Freiburg, Breisacher Strasse 64, 79106 Freiburg, Germany. ; Department of Biology, University of Konstanz, Universitatsstrasse 10, 78457 Konstanz, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25471880" target="_blank"〉PubMed〈/a〉

Description: The pluripotency factor Lin28 inhibits the biogenesis of the let-7 family of mammalian microRNAs. Lin28 is highly expressed in embryonic stem cells and has a fundamental role in regulation of development, glucose metabolism and tissue regeneration. Overexpression of Lin28 is correlated with the onset of numerous cancers, whereas let-7, a tumour suppressor, silences several human oncogenes. Lin28 binds to precursor let-7 (pre-let-7) hairpins, triggering the 3' oligo-uridylation activity of TUT4 and TUT7 (refs 10-12). The oligoU tail added to pre-let-7 serves as a decay signal, as it is rapidly degraded by Dis3l2 (refs 13, 14), a homologue of the catalytic subunit of the RNA exosome. The molecular basis of Lin28-mediated recruitment of TUT4 and TUT7 to pre-let-7 and its subsequent degradation by Dis3l2 is largely unknown. To examine the mechanism of Dis3l2 substrate recognition we determined the structure of mouse Dis3l2 in complex with an oligoU RNA to mimic the uridylated tail of pre-let-7. Three RNA-binding domains form an open funnel on one face of the catalytic domain that allows RNA to navigate a path to the active site different from that of its exosome counterpart. The resulting path reveals an extensive network of uracil-specific interactions spanning the first 12 nucleotides of an oligoU-tailed RNA. We identify three U-specificity zones that explain how Dis3l2 recognizes, binds and processes uridylated pre-let-7 in the final step of the Lin28-let-7 pathway.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4192074/" 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/PMC4192074/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Faehnle, Christopher R -- Walleshauser, Jack -- Joshua-Tor, Leemor -- P30 CA045508/CA/NCI NIH HHS/ -- P41 GM111244/GM/NIGMS NIH HHS/ -- T32 GM065094/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Oct 9;514(7521):252-6. doi: 10.1038/nature13553. Epub 2014 Aug 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] W. M. Keck Structural Biology Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [2] Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [3]. ; 1] W. M. Keck Structural Biology Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [2] Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [3] Watson School of Biological Science, Cold Spring Harbor, 1 Bungtown Road, New York 11724, USA [4]. ; 1] W. M. Keck Structural Biology Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [2] Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA [3] Watson School of Biological Science, Cold Spring Harbor, 1 Bungtown Road, New York 11724, USA [4] Howard Hughes Medical Institute, Cold Spring Harbor, 1 Bungtown Road, New York 11724, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25119025" target="_blank"〉PubMed〈/a〉

Description: Nitrate is a primary nutrient for plant growth, but its levels in soil can fluctuate by several orders of magnitude. Previous studies have identified Arabidopsis NRT1.1 as a dual-affinity nitrate transporter that can take up nitrate over a wide range of concentrations. The mode of action of NRT1.1 is controlled by phosphorylation of a key residue, Thr 101; however, how this post-translational modification switches the transporter between two affinity states remains unclear. Here we report the crystal structure of unphosphorylated NRT1.1, which reveals an unexpected homodimer in the inward-facing conformation. In this low-affinity state, the Thr 101 phosphorylation site is embedded in a pocket immediately adjacent to the dimer interface, linking the phosphorylation status of the transporter to its oligomeric state. Using a cell-based fluorescence resonance energy transfer assay, we show that functional NRT1.1 dimerizes in the cell membrane and that the phosphomimetic mutation of Thr 101 converts the protein into a monophasic high-affinity transporter by structurally decoupling the dimer. Together with analyses of the substrate transport tunnel, our results establish a phosphorylation-controlled dimerization switch that allows NRT1.1 to uptake nitrate with two distinct affinity modes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3968801/" 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/PMC3968801/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Ji -- Bankston, John R -- Payandeh, Jian -- Hinds, Thomas R -- Zagotta, William N -- Zheng, Ning -- NS074545/NS/NINDS NIH HHS/ -- R01EY10329/EY/NEI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Mar 6;507(7490):73-7. doi: 10.1038/nature13074. Epub 2014 Feb 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, Box 357280, University of Washington, Seattle, Washington 98195, USA. ; Department of Physiology and Biophysics, Box 357290, University of Washington, Seattle, Washington 98195, USA. ; 1] Department of Pharmacology, Box 357280, University of Washington, Seattle, Washington 98195, USA [2] Department of Structural Biology, Genentech Inc., South San Francisco, California 94080, USA. ; 1] Department of Pharmacology, Box 357280, University of Washington, Seattle, Washington 98195, USA [2] Howard Hughes Medical Institute, 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/24572362" target="_blank"〉PubMed〈/a〉

Description: Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 A resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kumazaki, Kaoru -- Chiba, Shinobu -- Takemoto, Mizuki -- Furukawa, Arata -- Nishiyama, Ken-ichi -- Sugano, Yasunori -- Mori, Takaharu -- Dohmae, Naoshi -- Hirata, Kunio -- Nakada-Nakura, Yoshiko -- Maturana, Andres D -- Tanaka, Yoshiki -- Mori, Hiroyuki -- Sugita, Yuji -- Arisaka, Fumio -- Ito, Koreaki -- Ishitani, Ryuichiro -- Tsukazaki, Tomoya -- Nureki, Osamu -- England -- Nature. 2014 May 22;509(7501):516-20. doi: 10.1038/nature13167. Epub 2014 Apr 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan [3]. ; 1] Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555, Japan [2]. ; 1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. ; Department of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan. ; Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan. ; Theoretical Molecular Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. ; Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. ; SR Life Science Instrumentation Unit, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan. ; Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan. ; Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan. ; Institute for Virus Research, Kyoto University, Shogoin Kawara-cho, Sakyo-ku, Kyoto 606-8507, Japan. ; Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan. ; Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555, Japan. ; 1] Department of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan [2] JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24739968" target="_blank"〉PubMed〈/a〉

Description: Cys-loop receptors are neurotransmitter-gated ion channels that are essential mediators of fast chemical neurotransmission and are associated with a large number of neurological diseases and disorders, as well as parasitic infections. Members of this ion channel superfamily mediate excitatory or inhibitory neurotransmission depending on their ligand and ion selectivity. Structural information for Cys-loop receptors comes from several sources including electron microscopic studies of the nicotinic acetylcholine receptor, high-resolution X-ray structures of extracellular domains and X-ray structures of bacterial orthologues. In 2011 our group published structures of the Caenorhabditis elegans glutamate-gated chloride channel (GluCl) in complex with the allosteric partial agonist ivermectin, which provided insights into the structure of a possibly open state of a eukaryotic Cys-loop receptor, the basis for anion selectivity and channel block, and the mechanism by which ivermectin and related molecules stabilize the open state and potentiate neurotransmitter binding. However, there remain unanswered questions about the mechanism of channel opening and closing, the location and nature of the shut ion channel gate, the transitions between the closed/resting, open/activated and closed/desensitized states, and the mechanism by which conformational changes are coupled between the extracellular, orthosteric agonist binding domain and the transmembrane, ion channel domain. Here we present two conformationally distinct structures of C. elegans GluCl in the absence of ivermectin. Structural comparisons reveal a quaternary activation mechanism arising from rigid-body movements between the extracellular and transmembrane domains and a mechanism for modulation of the receptor by phospholipids.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255919/" 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/PMC4255919/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Althoff, Thorsten -- Hibbs, Ryan E -- Banerjee, Surajit -- Gouaux, Eric -- F32 NS061404/NS/NINDS NIH HHS/ -- F32NS061404/NS/NINDS NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- R01 GM100400/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Aug 21;512(7514):333-7. doi: 10.1038/nature13669.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Vollum Institute, Oregon Health &Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA [2] Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, California 90095-1751, USA (T.A.); Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas 75390-9111, USA (R.E.H.). [3]. ; NE-CAT/Cornell University, 9700 South Cass Avenue, Building 436 E001, Argonne, Illinois 60439, USA. ; 1] Vollum Institute, Oregon Health &Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA [2] Howard Hughes Medical Institute, Oregon Health &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/25143115" target="_blank"〉PubMed〈/a〉

Description: Previous studies have established that the folding, structure and function of membrane proteins are influenced by their lipid environments and that lipids can bind to specific sites, for example, in potassium channels. Fundamental questions remain however regarding the extent of membrane protein selectivity towards lipids. Here we report a mass spectrometry approach designed to determine the selectivity of lipid binding to membrane protein complexes. We investigate the mechanosensitive channel of large conductance (MscL) from Mycobacterium tuberculosis and aquaporin Z (AqpZ) and the ammonia channel (AmtB) from Escherichia coli, using ion mobility mass spectrometry (IM-MS), which reports gas-phase collision cross-sections. We demonstrate that folded conformations of membrane protein complexes can exist in the gas phase. By resolving lipid-bound states, we then rank bound lipids on the basis of their ability to resist gas phase unfolding and thereby stabilize membrane protein structure. Lipids bind non-selectively and with high avidity to MscL, all imparting comparable stability; however, the highest-ranking lipid is phosphatidylinositol phosphate, in line with its proposed functional role in mechanosensation. AqpZ is also stabilized by many lipids, with cardiolipin imparting the most significant resistance to unfolding. Subsequently, through functional assays we show that cardiolipin modulates AqpZ function. Similar experiments identify AmtB as being highly selective for phosphatidylglycerol, prompting us to obtain an X-ray structure in this lipid membrane-like environment. The 2.3 A resolution structure, when compared with others obtained without lipid bound, reveals distinct conformational changes that re-position AmtB residues to interact with the lipid bilayer. Our results demonstrate that resistance to unfolding correlates with specific lipid-binding events, enabling a distinction to be made between lipids that merely bind from those that modulate membrane protein structure and/or function. We anticipate that these findings will be important not only for defining the selectivity of membrane proteins towards lipids, but also for understanding the role of lipids in modulating protein function or drug binding.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4087533/" 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/PMC4087533/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Laganowsky, Arthur -- Reading, Eamonn -- Allison, Timothy M -- Ulmschneider, Martin B -- Degiacomi, Matteo T -- Baldwin, Andrew J -- Robinson, Carol V -- 268851/European Research Council/International -- Medical Research Council/United Kingdom -- Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2014 Jun 5;510(7503):172-5. doi: 10.1038/nature13419.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 5QY, UK [2]. ; Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 5QY, UK. ; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24899312" target="_blank"〉PubMed〈/a〉

Description: The formation of branched lariat RNA is an evolutionarily conserved feature of splicing reactions for both group II and spliceosomal introns. The lariat is important for the fidelity of 5' splice-site selection and consists of a 2'-5' phosphodiester bond between a bulged adenosine and the 5' end of the intron. To gain insight into this ubiquitous intramolecular linkage, we determined the crystal structure of a eukaryotic group IIB intron in the lariat form at 3.7 A. This revealed that two tandem tetraloop-receptor interactions, eta-eta' and pi-pi', place domain VI in the core to position the lariat bond in the post-catalytic state. On the basis of structural and biochemical data, we propose that pi-pi' is a dynamic interaction that mediates the transition between the two steps of splicing, with eta-eta' serving an ancillary role. The structure also reveals a four-magnesium-ion cluster involved in both catalysis and positioning of the 5' end. Given the evolutionary relationship between group II and nuclear introns, it is likely that this active site configuration exists in the spliceosome as well.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197185/" 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/PMC4197185/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Robart, Aaron R -- Chan, Russell T -- Peters, Jessica K -- Rajashankar, Kanagalaghatta R -- Toor, Navtej -- 5R01GM102216/GM/NIGMS NIH HHS/ -- 5T32GM007240/GM/NIGMS NIH HHS/ -- 5T32GM008326/GM/NIGMS NIH HHS/ -- 8P41GM103403-10/GM/NIGMS NIH HHS/ -- P41 GM103403/GM/NIGMS NIH HHS/ -- R01 GM102216/GM/NIGMS NIH HHS/ -- T32 GM007240/GM/NIGMS NIH HHS/ -- T32 GM008326/GM/NIGMS NIH HHS/ -- England -- Nature. 2014 Oct 9;514(7521):193-7. doi: 10.1038/nature13790. Epub 2014 Sep 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA. ; NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois 60439, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25252982" target="_blank"〉PubMed〈/a〉

Description: SWEETs and their prokaryotic homologues are monosaccharide and disaccharide transporters that are present from Archaea to plants and humans. SWEETs play crucial roles in cellular sugar efflux processes: that is, in phloem loading, pollen nutrition and nectar secretion. Their bacterial homologues, which are called SemiSWEETs, are among the smallest known transporters. Here we show that SemiSWEET molecules, which consist of a triple-helix bundle, form symmetrical, parallel dimers, thereby generating the translocation pathway. Two SemiSWEET isoforms were crystallized, one in an apparently open state and one in an occluded state, indicating that SemiSWEETs and SWEETs are transporters that undergo rocking-type movements during the transport cycle. The topology of the triple-helix bundle is similar yet distinct to that of the basic building block of animal and plant major facilitator superfamily (MFS) transporters (for example, GLUTs and SUTs). This finding indicates two possibilities: that SWEETs and MFS transporters evolved from an ancestral triple-helix bundle or that the triple-helix bundle represents convergent evolution. In SemiSWEETs and SWEETs, two triple-helix bundles are arranged in a parallel configuration to produce the 6- and 6 + 1-transmembrane-helix pores, respectively. In the 12-transmembrane-helix MFS transporters, four triple-helix bundles are arranged into an alternating antiparallel configuration, resulting in a much larger 2 x 2 triple-helix bundle forming the pore. Given the similarity of SemiSWEETs and SWEETs to PQ-loop amino acid transporters and to mitochondrial pyruvate carriers (MPCs), the structures characterized here may also be relevant to other transporters in the MtN3 clan. The insight gained from the structures of these transporters and from the analysis of mutations of conserved residues will improve the understanding of the transport mechanism, as well as allow comparative studies of the different superfamilies involved in sugar transport and the evolution of transporters in general.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4300204/" 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/PMC4300204/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xu, Yan -- Tao, Yuyong -- Cheung, Lily S -- Fan, Chao -- Chen, Li-Qing -- Xu, Sophia -- Perry, Kay -- Frommer, Wolf B -- Feng, Liang -- P41 GM103403/GM/NIGMS NIH HHS/ -- England -- Nature. 2014 Nov 20;515(7527):448-52. doi: 10.1038/nature13670. Epub 2014 Sep 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Molecular and Cellular Physiology, 279 Campus Drive, Stanford University School of Medicine, Stanford, California 94305, USA [2]. ; 1] Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA [2]. ; Department of Molecular and Cellular Physiology, 279 Campus Drive, Stanford University School of Medicine, Stanford, California 94305, USA. ; Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA. ; Department of Biology, Stanford University, Stanford, California 94305, USA. ; NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA. ; 1] Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA [2] Department of Biology, Stanford University, Stanford, California 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25186729" target="_blank"〉PubMed〈/a〉