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  • Artikel  (167)
  • Models, Molecular  (167)
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  • 1
    Publikationsdatum: 2009-12-22
    Beschreibung: Broken chromosomes arising from DNA double-strand breaks result from endogenous events such as the production of reactive oxygen species during cellular metabolism, as well as from exogenous sources such as ionizing radiation. Left unrepaired or incorrectly repaired they can lead to genomic changes that may result in cell death or cancer. DNA-dependent protein kinase (DNA-PK), a holoenzyme that comprises the DNA-PK catalytic subunit (DNA-PKcs) and the heterodimer Ku70/Ku80, has a major role in non-homologous end joining-the main pathway in mammals used to repair double-strand breaks. DNA-PKcs is a serine/threonine protein kinase comprising a single polypeptide chain of 4,128 amino acids and belonging to the phosphatidylinositol-3-OH kinase (PI(3)K)-related protein family. DNA-PKcs is involved in the sensing and transmission of DNA damage signals to proteins such as p53, setting off events that lead to cell cycle arrest. It phosphorylates a wide range of substrates in vitro, including Ku70/Ku80, which is translocated along DNA. Here we present the crystal structure of human DNA-PKcs at 6.6 A resolution, in which the overall fold is clearly visible, to our knowledge, for the first time. The many alpha-helical HEAT repeats (helix-turn-helix motifs) facilitate bending and allow the polypeptide chain to fold into a hollow circular structure. The carboxy-terminal kinase domain is located on top of this structure, and a small HEAT repeat domain that probably binds DNA is inside. The structure provides a flexible cradle to promote DNA double-strand-break repair.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2811870/" 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/PMC2811870/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sibanda, Bancinyane L -- Chirgadze, Dimitri Y -- Blundell, Tom L -- 079281/Wellcome Trust/United Kingdom -- A3846/Cancer Research UK/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2010 Jan 7;463(7277):118-21. doi: 10.1038/nature08648. Epub 2009 Dec 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Cambridge, Old Addenbrooke's site, 80 Tennis Court Road, Cambridge CB2 1GA, UK. lynn@cryst.bioc.cam.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20023628" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antigens, Nuclear/chemistry ; Catalytic Domain ; Crystallography, X-Ray ; DNA/metabolism ; DNA Breaks, Double-Stranded ; DNA-Activated Protein Kinase/*chemistry/metabolism ; DNA-Binding Proteins/chemistry ; HeLa Cells ; *Helix-Turn-Helix Motifs ; Humans ; Models, Molecular ; Nuclear Proteins/*chemistry/metabolism ; Protein Folding ; Protein Structure, Secondary
    Print ISSN: 0028-0836
    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2008-03-14
    Beschreibung: Growth factors stimulate cells to take up excess nutrients and to use them for anabolic processes. The biochemical mechanism by which this is accomplished is not fully understood but it is initiated by phosphorylation of signalling proteins on tyrosine residues. Using a novel proteomic screen for phosphotyrosine-binding proteins, we have made the observation that an enzyme involved in glycolysis, the human M2 (fetal) isoform of pyruvate kinase (PKM2), binds directly and selectively to tyrosine-phosphorylated peptides. We show that binding of phosphotyrosine peptides to PKM2 results in release of the allosteric activator fructose-1,6-bisphosphate, leading to inhibition of PKM2 enzymatic activity. We also provide evidence that this regulation of PKM2 by phosphotyrosine signalling diverts glucose metabolites from energy production to anabolic processes when cells are stimulated by certain growth factors. Collectively, our results indicate that expression of this phosphotyrosine-binding form of pyruvate kinase is critical for rapid growth in cancer cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Christofk, Heather R -- Vander Heiden, Matthew G -- Wu, Ning -- Asara, John M -- Cantley, Lewis C -- R01 GM056203/GM/NIGMS NIH HHS/ -- T32 CA009172/CA/NCI NIH HHS/ -- England -- Nature. 2008 Mar 13;452(7184):181-6. doi: 10.1038/nature06667.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Systems Biology.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18337815" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Allosteric Site ; Animals ; Catalysis ; Cell Line ; Cell Proliferation/drug effects ; Cells/drug effects/metabolism ; HeLa Cells ; Humans ; Lysine/metabolism ; Models, Molecular ; Peptide Library ; Phosphotyrosine/*metabolism ; Protein Binding ; Proteomics ; Pyruvate Kinase/antagonists & inhibitors/*metabolism ; Substrate Specificity
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2008-11-18
    Beschreibung: Pentraxins are a family of ancient innate immune mediators conserved throughout evolution. The classical pentraxins include serum amyloid P component (SAP) and C-reactive protein, which are two of the acute-phase proteins synthesized in response to infection. Both recognize microbial pathogens and activate the classical complement pathway through C1q (refs 3 and 4). More recently, members of the pentraxin family were found to interact with cell-surface Fcgamma receptors (FcgammaR) and activate leukocyte-mediated phagocytosis. Here we describe the structural mechanism for pentraxin's binding to FcgammaR and its functional activation of FcgammaR-mediated phagocytosis and cytokine secretion. The complex structure between human SAP and FcgammaRIIa reveals a diagonally bound receptor on each SAP pentamer with both D1 and D2 domains of the receptor contacting the ridge helices from two SAP subunits. The 1:1 stoichiometry between SAP and FcgammaRIIa infers the requirement for multivalent pathogen binding for receptor aggregation. Mutational and binding studies show that pentraxins are diverse in their binding specificity for FcgammaR isoforms but conserved in their recognition structure. The shared binding site for SAP and IgG results in competition for FcgammaR binding and the inhibition of immune-complex-mediated phagocytosis by soluble pentraxins. These results establish antibody-like functions for pentraxins in the FcgammaR pathway, suggest an evolutionary overlap between the innate and adaptive immune systems, and have new therapeutic implications for autoimmune diseases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2688732/" 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/PMC2688732/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lu, Jinghua -- Marnell, Lorraine L -- Marjon, Kristopher D -- Mold, Carolyn -- Du Clos, Terry W -- Sun, Peter D -- R01 AI28358/AI/NIAID NIH HHS/ -- T32 AI007538/AI/NIAID NIH HHS/ -- Z01 AI000853-09/Intramural NIH HHS/ -- England -- Nature. 2008 Dec 18;456(7224):989-92. doi: 10.1038/nature07468. Epub 2008 Nov 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19011614" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Binding, Competitive ; C-Reactive Protein/chemistry/*immunology/*metabolism ; Crystallography, X-Ray ; Cytokines/immunology/secretion ; Humans ; Immunity, Innate/*immunology ; Immunoglobulin G/immunology/metabolism ; Macrophages/cytology/immunology ; Models, Molecular ; Phagocytosis ; Protein Conformation ; Receptors, IgG/chemistry/*immunology/*metabolism ; Serum Amyloid P-Component/chemistry/*immunology/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2008-11-28
    Beschreibung: Gibberellins (GAs) are phytohormones essential for many developmental processes in plants. A nuclear GA receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), has a primary structure similar to that of the hormone-sensitive lipases (HSLs). Here we analyse the crystal structure of Oryza sativa GID1 (OsGID1) bound with GA(4) and GA(3) at 1.9 A resolution. The overall structure of both complexes shows an alpha/beta-hydrolase fold similar to that of HSLs except for an amino-terminal lid. The GA-binding pocket corresponds to the substrate-binding site of HSLs. On the basis of the OsGID1 structure, we mutagenized important residues for GA binding and examined their binding activities. Almost all of them showed very little or no activity, confirming that the residues revealed by structural analysis are important for GA binding. The replacement of Ile 133 with Leu or Val-residues corresponding to those of the lycophyte Selaginella moellendorffii GID1s-caused an increase in the binding affinity for GA(34), a 2beta-hydroxylated GA(4). These observations indicate that GID1 originated from HSL and was further modified to have higher affinity and more strict selectivity for bioactive GAs by adapting the amino acids involved in GA binding in the course of plant evolution.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shimada, Asako -- Ueguchi-Tanaka, Miyako -- Nakatsu, Toru -- Nakajima, Masatoshi -- Naoe, Youichi -- Ohmiya, Hiroko -- Kato, Hiroaki -- Matsuoka, Makoto -- England -- Nature. 2008 Nov 27;456(7221):520-3. doi: 10.1038/nature07546.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19037316" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Crystallography, X-Ray ; Gibberellins/*chemistry/*metabolism ; Hydrolases/chemistry/metabolism ; Hydroxylation ; Models, Molecular ; Oryza/*chemistry/genetics/metabolism ; Plant Growth Regulators/*chemistry/*metabolism ; Plant Proteins/*chemistry/genetics/*metabolism ; Protein Binding ; Protein Conformation ; Substrate Specificity ; Two-Hybrid System Techniques
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2008-05-16
    Beschreibung: The potential impact of pandemic influenza makes effective measures to limit the spread and morbidity of virus infection a public health priority. Antiviral drugs are seen as essential requirements for control of initial influenza outbreaks caused by a new virus, and in pre-pandemic plans there is a heavy reliance on drug stockpiles. The principal target for these drugs is a virus surface glycoprotein, neuraminidase, which facilitates the release of nascent virus and thus the spread of infection. Oseltamivir (Tamiflu) and zanamivir (Relenza) are two currently used neuraminidase inhibitors that were developed using knowledge of the enzyme structure. It has been proposed that the closer such inhibitors resemble the natural substrate, the less likely they are to select drug-resistant mutant viruses that retain viability. However, there have been reports of drug-resistant mutant selection in vitro and from infected humans. We report here the enzymatic properties and crystal structures of neuraminidase mutants from H5N1-infected patients that explain the molecular basis of resistance. Our results show that these mutants are resistant to oseltamivir but still strongly inhibited by zanamivir owing to an altered hydrophobic pocket in the active site of the enzyme required for oseltamivir binding. Together with recent reports of the viability and pathogenesis of H5N1 (ref. 7) and H1N1 (ref. 8) viruses with neuraminidases carrying these mutations, our results indicate that it would be prudent for pandemic stockpiles of oseltamivir to be augmented by additional antiviral drugs, including zanamivir.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Collins, Patrick J -- Haire, Lesley F -- Lin, Yi Pu -- Liu, Junfeng -- Russell, Rupert J -- Walker, Philip A -- Skehel, John J -- Martin, Stephen R -- Hay, Alan J -- Gamblin, Steven J -- MC_U117512711/Medical Research Council/United Kingdom -- MC_U117512723/Medical Research Council/United Kingdom -- MC_U117570592/Medical Research Council/United Kingdom -- MC_U117584222/Medical Research Council/United Kingdom -- Medical Research Council/United Kingdom -- England -- Nature. 2008 Jun 26;453(7199):1258-61. doi: 10.1038/nature06956. Epub 2008 May 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18480754" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Crystallography, X-Ray ; *Drug Resistance, Viral ; Enzyme Inhibitors/chemistry/metabolism/pharmacology ; Humans ; Influenza A Virus, H1N1 Subtype/drug effects/enzymology/genetics ; Influenza A Virus, H5N1 Subtype/*drug effects/*enzymology/genetics ; Influenza, Human/virology ; Kinetics ; Models, Molecular ; Molecular Conformation ; Mutation/*genetics ; Neuraminidase/antagonists & inhibitors/*chemistry/*genetics/metabolism ; Oseltamivir/chemistry/metabolism/*pharmacology ; Protein Binding ; Zanamivir/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2008-09-02
    Beschreibung: Translation initiation, the rate-limiting step of the universal process of protein synthesis, proceeds through sequential, tightly regulated steps. In bacteria, the correct messenger RNA start site and the reading frame are selected when, with the help of initiation factors IF1, IF2 and IF3, the initiation codon is decoded in the peptidyl site of the 30S ribosomal subunit by the fMet-tRNA(fMet) anticodon. This yields a 30S initiation complex (30SIC) that is an intermediate in the formation of the 70S initiation complex (70SIC) that occurs on joining of the 50S ribosomal subunit to the 30SIC and release of the initiation factors. The localization of IF2 in the 30SIC has proved to be difficult so far using biochemical approaches, but could now be addressed using cryo-electron microscopy and advanced particle separation techniques on the basis of three-dimensional statistical analysis. Here we report the direct visualization of a 30SIC containing mRNA, fMet-tRNA(fMet) and initiation factors IF1 and GTP-bound IF2. We demonstrate that the fMet-tRNA(fMet) is held in a characteristic and precise position and conformation by two interactions that contribute to the formation of a stable complex: one involves the transfer RNA decoding stem which is buried in the 30S peptidyl site, and the other occurs between the carboxy-terminal domain of IF2 and the tRNA acceptor end. The structure provides insights into the mechanism of 70SIC assembly and rationalizes the rapid activation of GTP hydrolysis triggered on 30SIC-50S joining by showing that the GTP-binding domain of IF2 would directly face the GTPase-activated centre of the 50S subunit.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Simonetti, Angelita -- Marzi, Stefano -- Myasnikov, Alexander G -- Fabbretti, Attilio -- Yusupov, Marat -- Gualerzi, Claudio O -- Klaholz, Bruno P -- England -- Nature. 2008 Sep 18;455(7211):416-20. doi: 10.1038/nature07192. Epub 2008 Aug 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Genetics and of Molecular and Cellular Biology, Department of Structural Biology and Genomics, Illkirch F-67404, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18758445" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Cryoelectron Microscopy ; Crystallography, X-Ray ; Guanosine Triphosphate/chemistry/metabolism ; Models, Molecular ; Multiprotein Complexes/*chemistry/genetics/metabolism/*ultrastructure ; *Peptide Chain Initiation, Translational ; Prokaryotic Initiation Factor-1/chemistry/genetics/metabolism/ultrastructure ; Prokaryotic Initiation Factor-2/chemistry/genetics/metabolism/ultrastructure ; Protein Conformation ; RNA, Messenger/chemistry/genetics/metabolism ; RNA, Transfer, Met/chemistry/genetics/metabolism/ultrastructure ; Ribosome Subunits/chemistry/metabolism/ultrastructure ; Ribosomes/chemistry/*metabolism/*ultrastructure ; Thermus thermophilus/*enzymology/genetics/*ultrastructure
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-05-10
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ghirlanda, Giovanna -- England -- Nature. 2008 May 8;453(7192):164-6. doi: 10.1038/453164a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18464727" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Biochemistry/*methods ; Catalysis ; Computational Biology/*methods ; Directed Molecular Evolution/*methods ; Drug Design ; Drug Evaluation, Preclinical ; Enzymes/*chemistry/*metabolism ; Models, Molecular ; Protein Engineering/*methods
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Publikationsdatum: 2008-12-19
    Beschreibung: Here we report on a 3.0 A crystal structure of a ternary complex of wild-type Thermus thermophilus argonaute bound to a 5'-phosphorylated 21-nucleotide guide DNA and a 20-nucleotide target RNA containing cleavage-preventing mismatches at the 10-11 step. The seed segment (positions 2 to 8) adopts an A-helical-like Watson-Crick paired duplex, with both ends of the guide strand anchored in the complex. An arginine, inserted between guide-strand bases 10 and 11 in the binary complex, locking it in an inactive conformation, is released on ternary complex formation. The nucleic-acid-binding channel between the PAZ- and PIWI-containing lobes of argonaute widens on formation of a more open ternary complex. The relationship of structure to function was established by determining cleavage activity of ternary complexes containing position-dependent base mismatch, bulge and 2'-O-methyl modifications. Consistent with the geometry of the ternary complex, bulges residing in the seed segments of the target, but not the guide strand, were better accommodated and their complexes were catalytically active.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2765400/" 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/PMC2765400/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Yanli -- Juranek, Stefan -- Li, Haitao -- Sheng, Gang -- Tuschl, Thomas -- Patel, Dinshaw J -- R01 AI068776/AI/NIAID NIH HHS/ -- R01 AI068776-02/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Dec 18;456(7224):921-6. doi: 10.1038/nature07666.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial-Sloan Kettering Cancer Center, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19092929" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Proteins/*chemistry/genetics/*metabolism ; Base Pair Mismatch ; Base Pairing ; Base Sequence ; Crystallography, X-Ray ; DNA/chemistry/genetics/*metabolism ; Methylation ; Models, Molecular ; Phosphorylation ; Protein Conformation ; RNA/chemistry/genetics/*metabolism ; RNA Interference ; RNA-Induced Silencing Complex/*chemistry/genetics/*metabolism ; Substrate Specificity ; Thermus thermophilus/*chemistry
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2008-11-21
    Beschreibung: Replication forks are impeded by DNA damage and protein-nucleic acid complexes such as transcribing RNA polymerase. For example, head-on collision of the replisome with RNA polymerase results in replication fork arrest. However, co-directional collision of the replisome with RNA polymerase has little or no effect on fork progression. Here we examine co-directional collisions between a replisome and RNA polymerase in vitro. We show that the Escherichia coli replisome uses the RNA transcript as a primer to continue leading-strand synthesis after the collision with RNA polymerase that is displaced from the DNA. This action results in a discontinuity in the leading strand, yet the replisome remains intact and bound to DNA during the entire process. These findings underscore the notable plasticity by which the replisome operates to circumvent obstacles in its path and may explain why the leading strand is synthesized discontinuously in vivo.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2605185/" 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/PMC2605185/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pomerantz, Richard T -- O'Donnell, Mike -- R01 GM038839/GM/NIGMS NIH HHS/ -- R01 GM038839-21/GM/NIGMS NIH HHS/ -- R37 GM038839/GM/NIGMS NIH HHS/ -- R37 GM038839-20/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Dec 11;456(7223):762-6. doi: 10.1038/nature07527. Epub 2008 Nov 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Rockefeller University, Howard Hughes Medical Institute, 1230 York Avenue, New York, New York 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19020502" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): DNA Polymerase III/*metabolism ; DNA Replication ; DNA, Bacterial/metabolism ; DNA-Directed RNA Polymerases/*metabolism ; Escherichia coli/genetics/*metabolism ; Models, Molecular ; *Rna ; RNA, Bacterial/*metabolism ; RNA, Messenger/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2008-09-02
    Beschreibung: A common hallmark of human cancers is the overexpression of telomerase, a ribonucleoprotein complex that is responsible for maintaining the length and integrity of chromosome ends. Telomere length deregulation and telomerase activation is an early, and perhaps necessary, step in cancer cell evolution. Here we present the high-resolution structure of the Tribolium castaneum catalytic subunit of telomerase, TERT. The protein consists of three highly conserved domains, organized into a ring-like structure that shares common features with retroviral reverse transcriptases, viral RNA polymerases and B-family DNA polymerases. Domain organization places motifs implicated in substrate binding and catalysis in the interior of the ring, which can accommodate seven to eight bases of double-stranded nucleic acid. Modelling of an RNA-DNA heteroduplex in the interior of this ring demonstrates a perfect fit between the protein and the nucleic acid substrate, and positions the 3'-end of the DNA primer at the active site of the enzyme, providing evidence for the formation of an active telomerase elongation complex.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gillis, Andrew J -- Schuller, Anthony P -- Skordalakes, Emmanuel -- England -- Nature. 2008 Oct 2;455(7213):633-7. doi: 10.1038/nature07283. Epub 2008 Aug 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Gene Expression and Regulation Program, The Wistar Institute, 3601 Spruce Street, Philadelphia, Pennsylvania 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18758444" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Animals ; Binding Sites ; Catalysis ; Catalytic Domain ; Conserved Sequence ; Crystallization ; Crystallography, X-Ray ; Humans ; Models, Molecular ; Nucleotides/metabolism ; Protein Structure, Tertiary ; Telomerase/*chemistry/metabolism ; Tribolium/*enzymology
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 11
    Publikationsdatum: 2008-07-03
    Beschreibung: G-protein-coupled receptors have a major role in transmembrane signalling in most eukaryotes and many are important drug targets. Here we report the 2.7 A resolution crystal structure of a beta(1)-adrenergic receptor in complex with the high-affinity antagonist cyanopindolol. The modified turkey (Meleagris gallopavo) receptor was selected to be in its antagonist conformation and its thermostability improved by earlier limited mutagenesis. The ligand-binding pocket comprises 15 side chains from amino acid residues in 4 transmembrane alpha-helices and extracellular loop 2. This loop defines the entrance of the ligand-binding pocket and is stabilized by two disulphide bonds and a sodium ion. Binding of cyanopindolol to the beta(1)-adrenergic receptor and binding of carazolol to the beta(2)-adrenergic receptor involve similar interactions. A short well-defined helix in cytoplasmic loop 2, not observed in either rhodopsin or the beta(2)-adrenergic receptor, directly interacts by means of a tyrosine with the highly conserved DRY motif at the end of helix 3 that is essential for receptor activation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2923055/" 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/PMC2923055/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Warne, Tony -- Serrano-Vega, Maria J -- Baker, Jillian G -- Moukhametzianov, Rouslan -- Edwards, Patricia C -- Henderson, Richard -- Leslie, Andrew G W -- Tate, Christopher G -- Schertler, Gebhard F X -- MC_U105178937/Medical Research Council/United Kingdom -- MC_U105184322/Medical Research Council/United Kingdom -- MC_U105184325/Medical Research Council/United Kingdom -- MC_U105197215/Medical Research Council/United Kingdom -- U.1051.04.020(78937)/Medical Research Council/United Kingdom -- Wellcome Trust/United Kingdom -- England -- Nature. 2008 Jul 24;454(7203):486-91. doi: 10.1038/nature07101. Epub 2008 Jun 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18594507" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adrenergic beta-1 Receptor Agonists ; Adrenergic beta-1 Receptor Antagonists ; Adrenergic beta-Antagonists/chemistry/metabolism ; Amino Acid Motifs ; Animals ; Binding Sites ; Crystallization ; Crystallography, X-Ray ; Ligands ; Models, Molecular ; Mutant Proteins/chemistry/genetics/metabolism ; Mutation ; Pindolol/analogs & derivatives/chemistry/metabolism ; Propanolamines/chemistry/metabolism ; Protein Conformation ; Receptors, Adrenergic, beta-1/*chemistry/metabolism ; Thermodynamics ; Turkeys
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Publikationsdatum: 2008-02-29
    Beschreibung: A half-century after the determination of the first three-dimensional crystal structure of a protein, more than 40,000 structures ranging from single polypeptides to large assemblies have been reported. The challenge for crystallographers, however, remains the growing of a diffracting crystal. Here we report the 4.5-A resolution structure of a 22-MDa macromolecular assembly, the capsid of the infectious epsilon15 (epsilon15) particle, by single-particle electron cryomicroscopy. From this density map we constructed a complete backbone trace of its major capsid protein, gene product 7 (gp7). The structure reveals a similar protein architecture to that of other tailed double-stranded DNA viruses, even in the absence of detectable sequence similarity. However, the connectivity of the secondary structure elements (topology) in gp7 is unique. Protruding densities are observed around the two-fold axes that cannot be accounted for by gp7. A subsequent proteomic analysis of the whole virus identifies these densities as gp10, a 12-kDa protein. Its structure, location and high binding affinity to the capsid indicate that the gp10 dimer functions as a molecular staple between neighbouring capsomeres to ensure the particle's stability. Beyond epsilon15, this method potentially offers a new approach for modelling the backbone conformations of the protein subunits in other macromolecular assemblies at near-native solution states.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jiang, Wen -- Baker, Matthew L -- Jakana, Joanita -- Weigele, Peter R -- King, Jonathan -- Chiu, Wah -- England -- Nature. 2008 Feb 28;451(7182):1130-4. doi: 10.1038/nature06665.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA. jiang12@purdue.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18305544" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacteriophages/*chemistry/genetics/*ultrastructure ; Capsid/*chemistry/*ultrastructure ; Capsid Proteins/chemistry/ultrastructure ; Cryoelectron Microscopy ; DNA Viruses/chemistry/genetics/ultrastructure ; Models, Molecular ; Molecular Conformation ; Salmonella/*virology
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Publikationsdatum: 2008-05-27
    Beschreibung: Understanding the energetics of molecular interactions is fundamental to all of the central quests of structural biology including structure prediction and design, mapping evolutionary pathways, learning how mutations cause disease, drug design, and relating structure to function. Hydrogen-bonding is widely regarded as an important force in a membrane environment because of the low dielectric constant of membranes and a lack of competition from water. Indeed, polar residue substitutions are the most common disease-causing mutations in membrane proteins. Because of limited structural information and technical challenges, however, there have been few quantitative tests of hydrogen-bond strength in the context of large membrane proteins. Here we show, by using a double-mutant cycle analysis, that the average contribution of eight interhelical side-chain hydrogen-bonding interactions throughout bacteriorhodopsin is only 0.6 kcal mol(-1). In agreement with these experiments, we find that 4% of polar atoms in the non-polar core regions of membrane proteins have no hydrogen-bond partner and the lengths of buried hydrogen bonds in soluble proteins and membrane protein transmembrane regions are statistically identical. Our results indicate that most hydrogen-bond interactions in membrane proteins are only modestly stabilizing. Weak hydrogen-bonding should be reflected in considerations of membrane protein folding, dynamics, design, evolution and function.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2734483/" 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/PMC2734483/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Joh, Nathan Hyunjoong -- Min, Andrew -- Faham, Salem -- Whitelegge, Julian P -- Yang, Duan -- Woods, Virgil L -- Bowie, James U -- R01 CA081000/CA/NCI NIH HHS/ -- R01 CA081000-07/CA/NCI NIH HHS/ -- R01 CA081000-08/CA/NCI NIH HHS/ -- R01 CA081000-09/CA/NCI NIH HHS/ -- R01 GM063919/GM/NIGMS NIH HHS/ -- R01 GM063919-06/GM/NIGMS NIH HHS/ -- R01 GM063919-07/GM/NIGMS NIH HHS/ -- R01 GM063919-08/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Jun 26;453(7199):1266-70. doi: 10.1038/nature06977. Epub 2008 May 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, UCLA-DOE Center for Genomics and Proteomics, Molecular Biology Institute, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18500332" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacteriorhodopsins/chemistry/genetics/metabolism ; Crystallography, X-Ray ; Deuterium Exchange Measurement ; Hydrogen Bonding ; Membrane Proteins/*chemistry/genetics/*metabolism ; Models, Molecular ; Mutation/genetics ; Protein Folding ; Solubility ; Thermodynamics
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Publikationsdatum: 2008-09-06
    Beschreibung: Human cancer cells typically harbour multiple chromosomal aberrations, nucleotide substitutions and epigenetic modifications that drive malignant transformation. The Cancer Genome Atlas (TCGA) pilot project aims to assess the value of large-scale multi-dimensional analysis of these molecular characteristics in human cancer and to provide the data rapidly to the research community. Here we report the interim integrative analysis of DNA copy number, gene expression and DNA methylation aberrations in 206 glioblastomas--the most common type of adult brain cancer--and nucleotide sequence aberrations in 91 of the 206 glioblastomas. This analysis provides new insights into the roles of ERBB2, NF1 and TP53, uncovers frequent mutations of the phosphatidylinositol-3-OH kinase regulatory subunit gene PIK3R1, and provides a network view of the pathways altered in the development of glioblastoma. Furthermore, integration of mutation, DNA methylation and clinical treatment data reveals a link between MGMT promoter methylation and a hypermutator phenotype consequent to mismatch repair deficiency in treated glioblastomas, an observation with potential clinical implications. Together, these findings establish the feasibility and power of TCGA, demonstrating that it can rapidly expand knowledge of the molecular basis of cancer.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671642/" 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/PMC2671642/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cancer Genome Atlas Research Network -- R01 CA099041/CA/NCI NIH HHS/ -- R01 CA099041-05/CA/NCI NIH HHS/ -- T32 GM007753/GM/NIGMS NIH HHS/ -- U24 CA126543-01/CA/NCI NIH HHS/ -- U24 CA126544/CA/NCI NIH HHS/ -- U24 CA126544-01/CA/NCI NIH HHS/ -- U24 CA126546/CA/NCI NIH HHS/ -- U24 CA126546-01/CA/NCI NIH HHS/ -- U24 CA126551-01/CA/NCI NIH HHS/ -- U24 CA126554/CA/NCI NIH HHS/ -- U24 CA126554-01/CA/NCI NIH HHS/ -- U24 CA126561/CA/NCI NIH HHS/ -- U24 CA126561-01/CA/NCI NIH HHS/ -- U24 CA126563/CA/NCI NIH HHS/ -- U24 CA126563-01/CA/NCI NIH HHS/ -- U24CA126543/CA/NCI NIH HHS/ -- U24CA126544/CA/NCI NIH HHS/ -- U24CA126546/CA/NCI NIH HHS/ -- U24CA126551/CA/NCI NIH HHS/ -- U24CA126554/CA/NCI NIH HHS/ -- U24CA126561/CA/NCI NIH HHS/ -- U24CA126563/CA/NCI NIH HHS/ -- U54 HG003067/HG/NHGRI NIH HHS/ -- U54 HG003067-01/HG/NHGRI NIH HHS/ -- U54 HG003079/HG/NHGRI NIH HHS/ -- U54 HG003079-05/HG/NHGRI NIH HHS/ -- U54 HG003273/HG/NHGRI NIH HHS/ -- U54 HG003273-01/HG/NHGRI NIH HHS/ -- U54HG003067/HG/NHGRI NIH HHS/ -- U54HG003079/HG/NHGRI NIH HHS/ -- U54HG003273/HG/NHGRI NIH HHS/ -- England -- Nature. 2008 Oct 23;455(7216):1061-8. doi: 10.1038/nature07385. Epub 2008 Sep 4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18772890" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adolescent ; Adult ; Aged ; Aged, 80 and over ; Brain Neoplasms/*genetics ; DNA Methylation ; DNA Modification Methylases/genetics ; DNA Repair/genetics ; DNA Repair Enzymes/genetics ; Female ; Gene Dosage ; *Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Genes, erbB-1/genetics ; Genome, Human/genetics ; *Genomics ; Glioblastoma/*genetics ; Humans ; Male ; Middle Aged ; Models, Molecular ; Mutation/genetics ; Neurofibromin 1/genetics ; Phosphatidylinositol 3-Kinases/genetics ; Protein Structure, Tertiary ; Retrospective Studies ; Signal Transduction/genetics ; Tumor Suppressor Proteins/genetics
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Publikationsdatum: 2008-01-04
    Beschreibung: Typical 2-Cys peroxiredoxins (Prxs) have an important role in regulating hydrogen peroxide-mediated cell signalling. In this process, Prxs can become inactivated through the hyperoxidation of an active site Cys residue to Cys sulphinic acid. The unique repair of this moiety by sulphiredoxin (Srx) restores peroxidase activity and terminates the signal. The hyperoxidized form of Prx exists as a stable decameric structure with each active site buried. Therefore, it is unclear how Srx can access the sulphinic acid moiety. Here we present the 2.6 A crystal structure of the human Srx-PrxI complex. This complex reveals the complete unfolding of the carboxy terminus of Prx, and its unexpected packing onto the backside of Srx away from the Srx active site. Binding studies and activity analyses of site-directed mutants at this interface show that the interaction is required for repair to occur. Moreover, rearrangements in the Prx active site lead to a juxtaposition of the Prx Gly-Gly-Leu-Gly and Srx ATP-binding motifs, providing a structural basis for the first step of the catalytic mechanism. The results also suggest that the observed interactions may represent a common mode for other proteins to bind to Prxs.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2646140/" 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/PMC2646140/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jonsson, Thomas J -- Johnson, Lynnette C -- Lowther, W Todd -- R01 GM072866/GM/NIGMS NIH HHS/ -- R01 GM072866-03/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Jan 3;451(7174):98-101. doi: 10.1038/nature06415.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Structural Biology and Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18172504" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites/genetics ; Catalysis ; Crystallography, X-Ray ; Humans ; Models, Molecular ; Multiprotein Complexes/chemistry/genetics/metabolism ; Mutagenesis, Site-Directed ; Oxidation-Reduction ; Oxidoreductases/*chemistry/genetics/*metabolism ; Oxidoreductases Acting on Sulfur Group Donors ; Peroxiredoxins/*chemistry/genetics/*metabolism ; Protein Structure, Quaternary ; Structure-Activity Relationship
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Publikationsdatum: 2008-02-22
    Beschreibung: Messenger-RNA-directed protein synthesis is accomplished by the ribosome. In eubacteria, this complex process is initiated by a specialized transfer RNA charged with formylmethionine (tRNA(fMet)). The amino-terminal formylated methionine of all bacterial nascent polypeptides blocks the reactive amino group to prevent unfavourable side-reactions and to enhance the efficiency of translation initiation. The first enzymatic factor that processes nascent chains is peptide deformylase (PDF); it removes this formyl group as polypeptides emerge from the ribosomal tunnel and before the newly synthesized proteins can adopt their native fold, which may bury the N terminus. Next, the N-terminal methionine is excised by methionine aminopeptidase. Bacterial PDFs are metalloproteases sharing a conserved N-terminal catalytic domain. All Gram-negative bacteria, including Escherichia coli, possess class-1 PDFs characterized by a carboxy-terminal alpha-helical extension. Studies focusing on PDF as a target for antibacterial drugs have not revealed the mechanism of its co-translational mode of action despite indications in early work that it co-purifies with ribosomes. Here we provide biochemical evidence that E. coli PDF interacts directly with the ribosome via its C-terminal extension. Crystallographic analysis of the complex between the ribosome-interacting helix of PDF and the ribosome at 3.7 A resolution reveals that the enzyme orients its active site towards the ribosomal tunnel exit for efficient co-translational processing of emerging nascent chains. Furthermore, we have found that the interaction of PDF with the ribosome enhances cell viability. These results provide the structural basis for understanding the coupling between protein synthesis and enzymatic processing of nascent chains, and offer insights into the interplay of PDF with the ribosome-associated chaperone trigger factor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bingel-Erlenmeyer, Rouven -- Kohler, Rebecca -- Kramer, Gunter -- Sandikci, Arzu -- Antolic, Snjezana -- Maier, Timm -- Schaffitzel, Christiane -- Wiedmann, Brigitte -- Bukau, Bernd -- Ban, Nenad -- England -- Nature. 2008 Mar 6;452(7183):108-11. doi: 10.1038/nature06683. Epub 2008 Feb 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18288106" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amidohydrolases/*chemistry/deficiency/genetics/*metabolism ; Amino Acid Sequence ; Arabinose/metabolism ; Binding Sites ; Crystallography, X-Ray ; Escherichia coli/*enzymology/genetics/growth & development/metabolism ; Genetic Complementation Test ; Models, Biological ; Models, Molecular ; Molecular Sequence Data ; N-Formylmethionine/metabolism ; Peptidylprolyl Isomerase/metabolism ; Protein Binding ; *Protein Biosynthesis ; *Protein Processing, Post-Translational ; Protein Structure, Secondary ; RNA, Transfer, Met/genetics/metabolism ; Ribosome Subunits/chemistry/metabolism ; Ribosomes/*chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Publikationsdatum: 2008-10-31
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Whisstock, James C -- Bottomley, Stephen P -- England -- Nature. 2008 Oct 30;455(7217):1189-90. doi: 10.1038/4551189a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18972012" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amyloid/chemistry/metabolism ; Animals ; Antithrombin III/*chemistry/*metabolism ; Biopolymers/chemistry/metabolism ; Crystallography, X-Ray ; Dimerization ; Humans ; Models, Molecular ; Protein Conformation ; Protein Folding
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Publikationsdatum: 2008-07-04
    Beschreibung: Neurotrophins (NTs) are important regulators for the survival, differentiation and maintenance of different peripheral and central neurons. NTs bind to two distinct classes of glycosylated receptor: the p75 neurotrophin receptor (p75(NTR)) and tyrosine kinase receptors (Trks). Whereas p75(NTR) binds to all NTs, the Trk subtypes are specific for each NT. The question of whether NTs stimulate p75(NTR) by inducing receptor homodimerization is still under debate. Here we report the 2.6-A resolution crystal structure of neurotrophin-3 (NT-3) complexed to the ectodomain of glycosylated p75(NTR). In contrast to the previously reported asymmetric complex structure, which contains a dimer of nerve growth factor (NGF) bound to a single ectodomain of deglycosylated p75(NTR) (ref. 3), we show that NT-3 forms a central homodimer around which two glycosylated p75(NTR) molecules bind symmetrically. Symmetrical binding occurs along the NT-3 interfaces, resulting in a 2:2 ligand-receptor cluster. A comparison of the symmetrical and asymmetric structures reveals significant differences in ligand-receptor interactions and p75(NTR) conformations. Biochemical experiments indicate that both NT-3 and NGF bind to p75(NTR) with 2:2 stoichiometry in solution, whereas the 2:1 complexes are the result of artificial deglycosylation. We therefore propose that the symmetrical 2:2 complex reflects a native state of p75(NTR) activation at the cell surface. These results provide a model for NTs-p75(NTR) recognition and signal generation, as well as insights into coordination between p75(NTR) and Trks.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gong, Yong -- Cao, Peng -- Yu, Hong-jun -- Jiang, Tao -- England -- Nature. 2008 Aug 7;454(7205):789-93. doi: 10.1038/nature07089. Epub 2008 Jul 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18596692" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cell Line ; Crystallography, X-Ray ; Dimerization ; Glycosylation ; Humans ; Ligands ; Models, Molecular ; Neurotrophin 3/*chemistry/genetics/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Rats ; Receptor, Nerve Growth Factor/*chemistry/genetics/*metabolism ; Spodoptera
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Publikationsdatum: 2008-02-26
    Beschreibung: The psychosis associated with schizophrenia is characterized by alterations in sensory processing and perception. Some antipsychotic drugs were identified by their high affinity for serotonin 5-HT2A receptors (2AR). Drugs that interact with metabotropic glutamate receptors (mGluR) also have potential for the treatment of schizophrenia. The effects of hallucinogenic drugs, such as psilocybin and lysergic acid diethylamide, require the 2AR and resemble some of the core symptoms of schizophrenia. Here we show that the mGluR2 interacts through specific transmembrane helix domains with the 2AR, a member of an unrelated G-protein-coupled receptor family, to form functional complexes in brain cortex. The 2AR-mGluR2 complex triggers unique cellular responses when targeted by hallucinogenic drugs, and activation of mGluR2 abolishes hallucinogen-specific signalling and behavioural responses. In post-mortem human brain from untreated schizophrenic subjects, the 2AR is upregulated and the mGluR2 is downregulated, a pattern that could predispose to psychosis. These regulatory changes indicate that the 2AR-mGluR2 complex may be involved in the altered cortical processes of schizophrenia, and this complex is therefore a promising new target for the treatment of psychosis.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2743172/" 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/PMC2743172/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gonzalez-Maeso, Javier -- Ang, Rosalind L -- Yuen, Tony -- Chan, Pokman -- Weisstaub, Noelia V -- Lopez-Gimenez, Juan F -- Zhou, Mingming -- Okawa, Yuuya -- Callado, Luis F -- Milligan, Graeme -- Gingrich, Jay A -- Filizola, Marta -- Meana, J Javier -- Sealfon, Stuart C -- G9811527/Medical Research Council/United Kingdom -- P01 DA012923/DA/NIDA NIH HHS/ -- P01 DA012923-06A10004/DA/NIDA NIH HHS/ -- T32 DA007135/DA/NIDA NIH HHS/ -- T32 DA007135-25S1/DA/NIDA NIH HHS/ -- T32 GM062754/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Mar 6;452(7183):93-7. doi: 10.1038/nature06612. Epub 2008 Feb 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurology, Mount Sinai School of Medicine, New York, New York 10029, USA. javier.maeso@mssm.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18297054" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Brain/cytology/metabolism ; Cell Line ; Cells, Cultured ; Down-Regulation ; Hallucinogens/metabolism/pharmacology ; Humans ; Mice ; Models, Molecular ; Multiprotein Complexes/chemistry/genetics/metabolism ; Protein Binding ; Protein Structure, Tertiary ; Psychotic Disorders/drug therapy/genetics/*metabolism ; Receptor, Serotonin, 5-HT2A/analysis/deficiency/genetics/*metabolism ; Receptors, Metabotropic Glutamate/analysis/antagonists & ; inhibitors/genetics/*metabolism ; Schizophrenia/metabolism ; Signal Transduction/drug effects ; Up-Regulation
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Publikationsdatum: 2008-07-11
    Beschreibung: Structured RNAs embedded in the untranslated regions (UTRs) of messenger RNAs can regulate gene expression. In bacteria, control of a metabolite gene is mediated by the self-cleaving activity of a ribozyme embedded in its 5' UTR. This discovery has raised the question of whether gene-regulating ribozymes also exist in eukaryotic mRNAs. Here we show that highly active hammerhead ribozymes are present in the 3' UTRs of rodent C-type lectin type II (Clec2) genes. Using a hammerhead RNA motif search with relaxed delimitation of the non-conserved regions, we detected ribozyme sequences in which the invariant regions, in contrast to the previously identified continuous hammerheads, occur as two fragments separated by hundreds of nucleotides. Notably, a fragment pair can assemble to form an active hammerhead ribozyme structure between the translation termination and the polyadenylation signals within the 3' UTR. We demonstrate that this hammerhead structure can self-cleave both in vitro and in vivo, and is able to reduce protein expression in mouse cells. These results indicate that an unrecognized mechanism of post-transcriptional gene regulation involving association of discontinuous ribozyme sequences within an mRNA may be modulating the expression of several CLEC2 proteins that function in bone remodelling and the immune response of several mammals.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2612532/" 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/PMC2612532/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Martick, Monika -- Horan, Lucas H -- Noller, Harry F -- Scott, William G -- R01 AI043393/AI/NIAID NIH HHS/ -- R01 AI043393-09/AI/NIAID NIH HHS/ -- R01 GM087721/GM/NIGMS NIH HHS/ -- R01043393/PHS HHS/ -- England -- Nature. 2008 Aug 14;454(7206):899-902. doi: 10.1038/nature07117. Epub 2008 Jul 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Molecular Biology of RNA, University of California, Santa Cruz, California 95064, USA. mmartick@yahoo.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18615019" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3' Untranslated Regions/genetics ; Animals ; Down-Regulation ; Lectins, C-Type/genetics/metabolism ; Mice ; Models, Molecular ; NIH 3T3 Cells ; Nucleic Acid Conformation ; RNA, Catalytic/chemistry/*genetics/metabolism ; RNA, Messenger/chemistry/*genetics/metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 21
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    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-08-01
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kanner, Baruch I -- England -- Nature. 2008 Jul 31;454(7204):593-4. doi: 10.1038/454593a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18668099" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Proteins/*chemistry/*metabolism ; Galactose/metabolism ; *Ion Transport ; Models, Molecular ; Protein Structure, Tertiary ; Sodium/metabolism ; Sodium-Glucose Transport Proteins/*chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 22
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-08-16
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kapur, Shiven -- Khosla, Chaitan -- England -- Nature. 2008 Aug 14;454(7206):832-3. doi: 10.1038/454832a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18704072" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Anti-Bacterial Agents/*biosynthesis ; Enzymes/chemistry/*metabolism ; Models, Molecular ; Peptide Synthases/metabolism ; Polyketide Synthases/metabolism ; Protein Interaction Domains and Motifs
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 23
    Publikationsdatum: 2009-01-14
    Beschreibung: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340503/" 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/PMC4340503/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kelly, Bernard T -- McCoy, Airlie J -- Spate, Kira -- Miller, Sharon E -- Evans, Philip R -- Honing, Stefan -- Owen, David J -- 090909/Wellcome Trust/United Kingdom -- MC_U105178845/Medical Research Council/United Kingdom -- England -- Nature. 2008 Dec 18;456(7224):976-79. doi: 10.1038/nature07422.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19140243" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adaptor Protein Complex 2/*chemistry/genetics/*metabolism ; Amino Acid Motifs ; Animals ; Antigens, CD4/*chemistry/*metabolism ; Binding Sites ; Conserved Sequence ; *Endocytosis ; Humans ; Leucine/*metabolism ; Mice ; Models, Molecular ; Protein Binding ; Protein Conformation ; Protein Subunits/chemistry/genetics/metabolism ; Rats
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 24
    Publikationsdatum: 2008-02-01
    Beschreibung: The M2 protein from influenza A virus is a pH-activated proton channel that mediates acidification of the interior of viral particles entrapped in endosomes. M2 is the target of the anti-influenza drugs amantadine and rimantadine; recently, resistance to these drugs in humans, birds and pigs has reached more than 90% (ref. 1). Here we describe the crystal structure of the transmembrane-spanning region of the homotetrameric protein in the presence and absence of the channel-blocking drug amantadine. pH-dependent structural changes occur near a set of conserved His and Trp residues that are involved in proton gating. The drug-binding site is lined by residues that are mutated in amantadine-resistant viruses. Binding of amantadine physically occludes the pore, and might also perturb the pK(a) of the critical His residue. The structure provides a starting point for solving the problem of resistance to M2-channel blockers.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889492/" 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/PMC3889492/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stouffer, Amanda L -- Acharya, Rudresh -- Salom, David -- Levine, Anna S -- Di Costanzo, Luigi -- Soto, Cinque S -- Tereshko, Valentina -- Nanda, Vikas -- Stayrook, Steven -- DeGrado, William F -- R37 GM054616/GM/NIGMS NIH HHS/ -- T32 GM008275/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Jan 31;451(7178):596-9. doi: 10.1038/nature06528.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18235504" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amantadine/chemistry/metabolism/pharmacology ; Crystallography, X-Ray ; Drug Resistance, Viral/genetics ; Histidine/metabolism ; Hydrogen-Ion Concentration ; Influenza A virus/*chemistry/genetics/metabolism ; Ion Channel Gating/drug effects ; Models, Molecular ; Protein Structure, Quaternary ; Protons ; Structure-Activity Relationship ; Tryptophan/metabolism ; Viral Matrix Proteins/*antagonists & inhibitors/*chemistry/genetics/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 25
    Publikationsdatum: 2008-11-07
    Beschreibung: The recent emergence of highly pathogenic avian (H5N1) influenza viruses, their epizootic and panzootic nature, and their association with lethal human infections have raised significant global health concerns. Several studies have underlined the importance of non-structural protein NS1 in the increased pathogenicity and virulence of these strains. NS1, which consists of two domains-a double-stranded RNA (dsRNA) binding domain and the effector domain, separated through a linker-is an antagonist of antiviral type-I interferon response in the host. Here we report the X-ray structure of the full-length NS1 from an H5N1 strain (A/Vietnam/1203/2004) that was associated with 60% of human deaths in an outbreak in Vietnam. Compared to the individually determined structures of the RNA binding domain and the effector domain from non-H5N1 strains, the RNA binding domain within H5N1 NS1 exhibits modest structural changes, while the H5N1 effector domain shows significant alteration, particularly in the dimeric interface. Although both domains in the full-length NS1 individually participate in dimeric interactions, an unexpected finding is that these interactions result in the formation of a chain of NS1 molecules instead of distinct dimeric units. Three such chains in the crystal interact with one another extensively to form a tubular organization of similar dimensions to that observed in the cryo-electron microscopy images of NS1 in the presence of dsRNA. The tubular oligomeric organization of NS1, in which residues implicated in dsRNA binding face a 20-A-wide central tunnel, provides a plausible mechanism for how NS1 sequesters varying lengths of dsRNA, to counter cellular antiviral dsRNA response pathways, while simultaneously interacting with other cellular ligands during an infection.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2798118/" 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/PMC2798118/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bornholdt, Zachary A -- Prasad, B V Venkataram -- AI36040/AI/NIAID NIH HHS/ -- R37 AI036040/AI/NIAID NIH HHS/ -- R37 AI036040-21/AI/NIAID NIH HHS/ -- RR002250/RR/NCRR NIH HHS/ -- England -- Nature. 2008 Dec 18;456(7224):985-8. doi: 10.1038/nature07444. Epub 2008 Nov 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18987632" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Cryoelectron Microscopy ; Crystallography, X-Ray ; Humans ; Influenza A Virus, H5N1 Subtype/*chemistry/*pathogenicity ; Influenza, Human/epidemiology/virology ; Models, Molecular ; Protein Multimerization ; Protein Structure, Tertiary ; Vietnam/epidemiology ; Viral Nonstructural Proteins/*chemistry/ultrastructure ; Virulence ; Virulence Factors
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 26
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-10-25
    Beschreibung: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3242476/" 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/PMC3242476/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Green, Douglas R -- Chipuk, Jerry E -- F32 CA101444/CA/NCI NIH HHS/ -- R01 AI040646/AI/NIAID NIH HHS/ -- R01 AI040646-14/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Oct 23;455(7216):1047-9. doi: 10.1038/4551047a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18948940" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; *Apoptosis ; Apoptosis Regulatory Proteins/*metabolism ; BH3 Interacting Domain Death Agonist Protein/metabolism ; Membrane Proteins/*metabolism ; Mitochondrial Membranes/*metabolism ; Models, Molecular ; Permeability ; Protein Binding ; Proto-Oncogene Proteins/*metabolism ; bcl-2-Associated X Protein/chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    Publikationsdatum: 2008-09-17
    Beschreibung: Hedgehog (Hh) proteins specify tissue pattern in metazoan embryos by forming gradients that emanate from discrete sites of expression and elicit concentration-dependent cellular differentiation or proliferation responses. Cellular responses to Hh and the movement of Hh through tissues are both precisely regulated, and abnormal Hh signalling has been implicated in human birth defects and cancer. Hh signalling is mediated by its amino-terminal domain (HhN), which is dually lipidated and secreted as part of a multivalent lipoprotein particle. Reception of the HhN signal is modulated by several cell-surface proteins on responding cells, including Patched (Ptc), Smoothened (Smo), Ihog (known as CDO or CDON in mammals) and the vertebrate-specific proteins Hip (also known as Hhip) and Gas1 (ref. 11). Drosophila Ihog and its vertebrate homologues CDO and BOC contain multiple immunoglobulin and fibronectin type III (FNIII) repeats, and the first FNIII repeat of Ihog binds Drosophila HhN in a heparin-dependent manner. Surprisingly, pull-down experiments suggest that a mammalian Sonic hedgehog N-terminal domain (ShhN) binds a non-orthologous FNIII repeat of CDO. Here we report biochemical, biophysical and X-ray structural studies of a complex between ShhN and the third FNIII repeat of CDO. We show that the ShhN-CDO interaction is completely unlike the HhN-Ihog interaction and requires calcium, which binds at a previously undetected site on ShhN. This site is conserved in nearly all Hh proteins and is a hotspot for mediating interactions between ShhN and CDO, Ptc, Hip and Gas1. Mutations in vertebrate Hh proteins causing holoprosencephaly and brachydactyly type A1 map to this calcium-binding site and disrupt interactions with these partners.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679680/" 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/PMC2679680/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McLellan, Jason S -- Zheng, Xiaoyan -- Hauk, Glenn -- Ghirlando, Rodolfo -- Beachy, Philip A -- Leahy, Daniel J -- R01 HD055545/HD/NICHD NIH HHS/ -- Z99 DK999999/Intramural NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Oct 16;455(7215):979-83. doi: 10.1038/nature07358. Epub 2008 Sep 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18794898" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding Sites ; Calcium/metabolism ; Cell Adhesion Molecules/chemistry/metabolism ; Cell Cycle Proteins/chemistry/metabolism ; Cell Line ; *Conserved Sequence ; Crystallography, X-Ray ; Drosophila Proteins/*chemistry/*metabolism ; Drosophila melanogaster/chemistry ; Fibronectins/chemistry ; GPI-Linked Proteins ; Hedgehog Proteins/*chemistry/genetics/*metabolism ; Humans ; Immunoglobulin G/chemistry/metabolism ; Membrane Glycoproteins/*chemistry/*metabolism ; Membrane Proteins/chemistry/metabolism ; Mice ; Models, Molecular ; Protein Binding/genetics ; Protein Structure, Tertiary ; Receptors, Cell Surface/*chemistry/*metabolism ; *Sequence Homology, Amino Acid ; Signal Transduction ; Tumor Suppressor Proteins/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 28
    Publikationsdatum: 2008-11-14
    Beschreibung: Voltage-activated sodium (Na(v)) channels are crucial for the generation and propagation of nerve impulses, and as such are widely targeted by toxins and drugs. The four voltage sensors in Na(v) channels have distinct amino acid sequences, raising fundamental questions about their relative contributions to the function and pharmacology of the channel. Here we use four-fold symmetric voltage-activated potassium (K(v)) channels as reporters to examine the contributions of individual S3b-S4 paddle motifs within Na(v) channel voltage sensors to the kinetics of voltage sensor activation and to forming toxin receptors. Our results uncover binding sites for toxins from tarantula and scorpion venom on each of the four paddle motifs in Na(v) channels, and reveal how paddle-specific interactions can be used to reshape Na(v) channel activity. One paddle motif is unique in that it slows voltage sensor activation, and toxins selectively targeting this motif impede Na(v) channel inactivation. This reporter approach and the principles that emerge will be useful in developing new drugs for treating pain and Na(v) channelopathies.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2587061/" 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/PMC2587061/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bosmans, Frank -- Martin-Eauclaire, Marie-France -- Swartz, Kenton J -- ZIA NS003017-03/Intramural NIH HHS/ -- England -- Nature. 2008 Nov 13;456(7219):202-8. doi: 10.1038/nature07473.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19005548" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Animals ; Ion Channel Gating/*drug effects ; Models, Molecular ; Mutagenesis ; Potassium Channels, Voltage-Gated/genetics/metabolism ; Protein Interaction Domains and Motifs/genetics/physiology ; Rats ; Recombinant Fusion Proteins/genetics/metabolism ; Scorpion Venoms/pharmacology ; Sodium Channels/genetics/*metabolism ; Spider Venoms/pharmacology ; Xenopus
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Publikationsdatum: 2008-11-07
    Beschreibung: Xeroderma pigmentosum is a monogenic disease characterized by hypersensitivity to ultraviolet light. The cells of xeroderma pigmentosum patients are defective in nucleotide excision repair, limiting their capacity to eliminate ultraviolet-induced DNA damage, and resulting in a strong predisposition to develop skin cancers. The use of rare cutting DNA endonucleases-such as homing endonucleases, also known as meganucleases-constitutes one possible strategy for repairing DNA lesions. Homing endonucleases have emerged as highly specific molecular scalpels that recognize and cleave DNA sites, promoting efficient homologous gene targeting through double-strand-break-induced homologous recombination. Here we describe two engineered heterodimeric derivatives of the homing endonuclease I-CreI, produced by a semi-rational approach. These two molecules-Amel3-Amel4 and Ini3-Ini4-cleave DNA from the human XPC gene (xeroderma pigmentosum group C), in vitro and in vivo. Crystal structures of the I-CreI variants complexed with intact and cleaved XPC target DNA suggest that the mechanism of DNA recognition and cleavage by the engineered homing endonucleases is similar to that of the wild-type I-CreI. Furthermore, these derivatives induced high levels of specific gene targeting in mammalian cells while displaying no obvious genotoxicity. Thus, homing endonucleases can be designed to recognize and cleave the DNA sequences of specific genes, opening up new possibilities for genome engineering and gene therapy in xeroderma pigmentosum patients whose illness can be treated ex vivo.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Redondo, Pilar -- Prieto, Jesus -- Munoz, Ines G -- Alibes, Andreu -- Stricher, Francois -- Serrano, Luis -- Cabaniols, Jean-Pierre -- Daboussi, Fayza -- Arnould, Sylvain -- Perez, Christophe -- Duchateau, Philippe -- Paques, Frederic -- Blanco, Francisco J -- Montoya, Guillermo -- England -- Nature. 2008 Nov 6;456(7218):107-11. doi: 10.1038/nature07343.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Macromolecular Crystallography Group, Spanish National Cancer Research Centre (CNIO), c/Melchor Fdez. Almagro 3, 28029 Madrid, Spain.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18987743" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; CHO Cells ; Cell Line ; Cricetinae ; Cricetulus ; Crystallography, X-Ray ; DNA/chemistry/*genetics/*metabolism ; DNA Repair ; DNA Restriction Enzymes/*chemistry/genetics/*metabolism/toxicity ; DNA-Binding Proteins/*genetics ; Enzyme Stability ; *Genetic Engineering ; Humans ; Models, Molecular ; Phosphorylation ; Protein Multimerization ; Substrate Specificity ; Xeroderma Pigmentosum/*genetics
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Publikationsdatum: 2008-06-13
    Beschreibung: In modern organisms, protein enzymes are solely responsible for the aminoacylation of transfer RNA. However, the evolution of protein synthesis in the RNA world required RNAs capable of catalysing this reaction. Ribozymes that aminoacylate RNA by using activated amino acids have been discovered through selection in vitro. Flexizyme is a 45-nucleotide ribozyme capable of charging tRNA in trans with various activated l-phenylalanine derivatives. In addition to a more than 10(5) rate enhancement and more than 10(4)-fold discrimination against some non-cognate amino acids, this ribozyme achieves good regioselectivity: of all the hydroxyl groups of a tRNA, it exclusively aminoacylates the terminal 3'-OH. Here we report the 2.8-A resolution structure of flexizyme fused to a substrate RNA. Together with randomization of ribozyme core residues and reselection, this structure shows that very few nucleotides are needed for the aminoacylation of specific tRNAs. Although it primarily recognizes tRNA through base-pairing with the CCA terminus of the tRNA molecule, flexizyme makes numerous local interactions to position the acceptor end of tRNA precisely. A comparison of two crystallographically independent flexizyme conformations, only one of which appears capable of binding activated phenylalanine, suggests that this ribozyme may achieve enhanced specificity by coupling active-site folding to tRNA docking. Such a mechanism would be reminiscent of the mutually induced fit of tRNA and protein employed by some aminoacyl-tRNA synthetases to increase specificity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xiao, Hong -- Murakami, Hiroshi -- Suga, Hiroaki -- Ferre-D'Amare, Adrian R -- England -- Nature. 2008 Jul 17;454(7202):358-61. doi: 10.1038/nature07033. Epub 2008 Jun 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109-1024, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18548004" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acyl-tRNA Synthetases/chemistry/metabolism ; Base Sequence ; Binding Sites ; Escherichia coli/enzymology ; Models, Molecular ; Nucleic Acid Conformation ; Protein Folding ; Protein Structure, Tertiary ; RNA, Catalytic/chemistry/genetics/*metabolism ; RNA, Transfer/chemistry/genetics/*metabolism ; *Transfer RNA Aminoacylation
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Publikationsdatum: 2008-07-29
    Beschreibung: Epac proteins are activated by binding of the second messenger cAMP and then act as guanine nucleotide exchange factors for Rap proteins. The Epac proteins are involved in the regulation of cell adhesion and insulin secretion. Here we have determined the structure of Epac2 in complex with a cAMP analogue (Sp-cAMPS) and RAP1B by X-ray crystallography and single particle electron microscopy. The structure represents the cAMP activated state of the Epac2 protein with the RAP1B protein trapped in the course of the exchange reaction. Comparison with the inactive conformation reveals that cAMP binding causes conformational changes that allow the cyclic nucleotide binding domain to swing from a position blocking the Rap binding site towards a docking site at the Ras exchange motif domain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rehmann, Holger -- Arias-Palomo, Ernesto -- Hadders, Michael A -- Schwede, Frank -- Llorca, Oscar -- Bos, Johannes L -- England -- Nature. 2008 Sep 4;455(7209):124-7. doi: 10.1038/nature07187. Epub 2008 Jul 27.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiological Chemistry, Centre for Biomedical Genetics and Cancer Genomics Centre, University Medical Center, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands. h.rehmann@UMCutrecht.nl〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18660803" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Animals ; Binding Sites ; Carrier Proteins/*chemistry/*metabolism/ultrastructure ; Crystallography, X-Ray ; Cyclic AMP/*analogs & derivatives/chemistry/metabolism ; Enzyme Activation ; Guanine Nucleotide Exchange Factors/*chemistry/*metabolism/ultrastructure ; Humans ; Mice ; Microscopy, Electron ; Models, Molecular ; Protein Binding ; Protein Conformation ; Thionucleotides/*chemistry/*metabolism ; rap GTP-Binding Proteins/chemistry/*metabolism/ultrastructure
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 32
    Publikationsdatum: 2008-03-07
    Beschreibung: Carbonic anhydrase, a zinc enzyme found in organisms from all kingdoms, catalyses the reversible hydration of carbon dioxide and is used for inorganic carbon acquisition by phytoplankton. In the oceans, where zinc is nearly depleted, diatoms use cadmium as a catalytic metal atom in cadmium carbonic anhydrase (CDCA). Here we report the crystal structures of CDCA in four distinct forms: cadmium-bound, zinc-bound, metal-free and acetate-bound. Despite lack of sequence homology, CDCA is a structural mimic of a functional beta-carbonic anhydrase dimer, with striking similarity in the spatial organization of the active site residues. CDCA readily exchanges cadmium and zinc at its active site--an apparently unique adaptation to oceanic life that is explained by a stable opening of the metal coordinating site in the absence of metal. Given the central role of diatoms in exporting carbon to the deep sea, their use of cadmium in an enzyme critical for carbon acquisition establishes a remarkable link between the global cycles of cadmium and carbon.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xu, Yan -- Feng, Liang -- Jeffrey, Philip D -- Shi, Yigong -- Morel, Francois M M -- England -- Nature. 2008 Mar 6;452(7183):56-61. doi: 10.1038/nature06636.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Ecology and Evolutionary Biology, Princeton University, New Jersey 08544, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18322527" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acetates/metabolism ; Binding Sites ; Cadmium/*metabolism ; Carbonic Anhydrases/*chemistry/*metabolism ; Catalysis ; Crystallography, X-Ray ; Diatoms/*enzymology ; Dimerization ; Kinetics ; Marine Biology ; Models, Molecular ; Molecular Mimicry ; Protein Structure, Secondary ; Seawater/*microbiology ; Zinc/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 33
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    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-11-21
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mellgren, Ronald L -- England -- Nature. 2008 Nov 20;456(7220):337-8. doi: 10.1038/456337a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19020611" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Biocatalysis ; Calcium/metabolism ; Calcium-Binding Proteins/*chemistry/*metabolism ; Calpain/*antagonists & inhibitors/chemistry/*metabolism ; *Catalytic Domain ; Crystallography, X-Ray ; Models, Molecular ; Peptide Fragments/chemistry/metabolism ; Protein Binding ; Protein Multimerization ; Rats
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 34
    Publikationsdatum: 2008-10-17
    Beschreibung: Repeating intermolecular protein association by means of beta-sheet expansion is the mechanism underlying a multitude of diseases including Alzheimer's, Huntington's and Parkinson's and the prion encephalopathies. A family of proteins, known as the serpins, also forms large stable multimers by ordered beta-sheet linkages leading to intracellular accretion and disease. These 'serpinopathies' include early-onset dementia caused by mutations in neuroserpin, liver cirrhosis and emphysema caused by mutations in alpha(1)-antitrypsin (alpha(1)AT), and thrombosis caused by mutations in antithrombin. Serpin structure and function are quite well understood, and the family has therefore become a model system for understanding the beta-sheet expansion disorders collectively known as the conformational diseases. To develop strategies to prevent and reverse these disorders, it is necessary to determine the structural basis of the intermolecular linkage and of the pathogenic monomeric state. Here we report the crystallographic structure of a stable serpin dimer which reveals a domain swap of more than 50 residues, including two long antiparallel beta-strands inserting in the centre of the principal beta-sheet of the neighbouring monomer. This structure explains the extreme stability of serpin polymers, the molecular basis of their rapid propagation, and provides critical new insights into the structural changes which initiate irreversible beta-sheet expansion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yamasaki, Masayuki -- Li, Wei -- Johnson, Daniel J D -- Huntington, James A -- G0801899/Medical Research Council/United Kingdom -- England -- Nature. 2008 Oct 30;455(7217):1255-8. doi: 10.1038/nature07394. Epub 2008 Oct 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of Cambridge, Department of Haematology, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18923394" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antithrombin III/*chemistry/*metabolism ; Biopolymers/chemistry/metabolism ; Crystallography, X-Ray ; Dimerization ; Humans ; Models, Molecular ; Protein Conformation
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  • 35
    Publikationsdatum: 2008-12-19
    Beschreibung: The role of conformational changes in explaining the huge catalytic power of enzymes is currently one of the most challenging questions in biology. Although it is now widely regarded that enzymes modulate reaction rates by means of short- and long-range protein motions, it is almost impossible to distinguish between conformational changes and catalysis. We have solved this problem using the chlorophyll biosynthetic enzyme NADPH:protochlorophyllide (Pchlide) oxidoreductase, which catalyses a unique light-driven reaction involving hydride and proton transfers. Here we report that prior excitation of the enzyme-substrate complex with a laser pulse induces a more favourable conformation of the active site, enabling the coupled hydride and proton transfer reactions to occur. This effect, which is triggered during the Pchlide excited-state lifetime and persists on a long timescale, switches the enzyme into an active state characterized by a high rate and quantum yield of formation of a catalytic intermediate. The corresponding spectral changes in the mid-infrared following the absorption of one photon reveal significant conformational changes in the enzyme, illustrating the importance of flexibility and dynamics in the structure of enzymes for their function.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sytina, Olga A -- Heyes, Derren J -- Hunter, C Neil -- Alexandre, Maxime T -- van Stokkum, Ivo H M -- van Grondelle, Rienk -- Groot, Marie Louise -- Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2008 Dec 18;456(7224):1001-4. doi: 10.1038/nature07354.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19092933" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Biocatalysis/radiation effects ; Catalytic Domain/radiation effects ; *Light ; Models, Molecular ; Oxidoreductases Acting on CH-CH Group Donors/chemistry/*metabolism/*radiation ; effects ; Protein Conformation/radiation effects ; Protons ; Structure-Activity Relationship ; Synechocystis/*enzymology ; Time Factors
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 36
    Publikationsdatum: 2008-04-25
    Beschreibung: Escherichia coli AlkB and its human homologues ABH2 and ABH3 repair DNA/RNA base lesions by using a direct oxidative dealkylation mechanism. ABH2 has the primary role of guarding mammalian genomes against 1-meA damage by repairing this lesion in double-stranded DNA (dsDNA), whereas AlkB and ABH3 preferentially repair single-stranded DNA (ssDNA) lesions and can repair damaged bases in RNA. Here we show the first crystal structures of AlkB-dsDNA and ABH2-dsDNA complexes, stabilized by a chemical cross-linking strategy. This study reveals that AlkB uses an unprecedented base-flipping mechanism to access the damaged base: it squeezes together the two bases flanking the flipped-out one to maintain the base stack, explaining the preference of AlkB for repairing ssDNA lesions over dsDNA ones. In addition, the first crystal structure of ABH2, presented here, provides a structural basis for designing inhibitors of this human DNA repair protein.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2587245/" 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/PMC2587245/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yang, Cai-Guang -- Yi, Chengqi -- Duguid, Erica M -- Sullivan, Christopher T -- Jian, Xing -- Rice, Phoebe A -- He, Chuan -- GM071440/GM/NIGMS NIH HHS/ -- R01 GM071440/GM/NIGMS NIH HHS/ -- R01 GM071440-03/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Apr 24;452(7190):961-5. doi: 10.1038/nature06889.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, 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/18432238" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenine/analogs & derivatives/metabolism ; Binding Sites ; Cross-Linking Reagents/chemistry ; Crystallography, X-Ray ; DNA/chemistry/*metabolism ; DNA Damage ; DNA Repair ; DNA Repair Enzymes/*chemistry/metabolism ; DNA-Binding Proteins/chemistry/metabolism ; Dioxygenases/*chemistry/*metabolism ; Escherichia coli Proteins/*chemistry/*metabolism ; Humans ; Mixed Function Oxygenases/*chemistry/*metabolism ; Models, Molecular ; Protein Binding ; RNA/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 37
    Publikationsdatum: 2008-10-14
    Beschreibung: P-type ATPases pump ions across membranes, generating steep electrochemical gradients that are essential for the function of all cells. Access to the ion-binding sites within the pumps alternates between the two sides of the membrane to avoid the dissipation of the gradients that would occur during simultaneous access. In Na(+),K(+)-ATPase pumps treated with the marine agent palytoxin, this strict alternation is disrupted and binding sites are sometimes simultaneously accessible from both sides of the membrane, transforming the pumps into ion channels (see, for example, refs 2, 3). Current recordings in these channels can monitor accessibility of introduced cysteine residues to water-soluble sulphydryl-specific reagents. We found previously that Na(+),K(+) pump-channels open to the extracellular surface through a deep and wide vestibule that emanates from a narrower pathway between transmembrane helices 4 and 6 (TM4 and TM6). Here we report that cysteine scans from TM1 to TM6 reveal a single unbroken cation pathway that traverses palytoxin-bound Na(+),K(+) pump-channels from one side of the membrane to the other. This pathway comprises residues from TM1, TM2, TM4 and TM6, passes through ion-binding site II, and is probably conserved in structurally and evolutionarily related P-type pumps, such as sarcoplasmic- and endoplasmic-reticulum Ca(2+)-ATPases and H(+),K(+)-ATPases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2585603/" 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/PMC2585603/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Takeuchi, Ayako -- Reyes, Nicolas -- Artigas, Pablo -- Gadsby, David C -- R01 HL036783/HL/NHLBI NIH HHS/ -- R01 HL036783-21/HL/NHLBI NIH HHS/ -- England -- Nature. 2008 Nov 20;456(7220):413-6. doi: 10.1038/nature07350. Epub 2008 Oct 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Cardiac/Membrane Physiology, The Rockefeller University, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18849964" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acrylamides/metabolism/pharmacology ; Animals ; Binding Sites ; Cell Membrane/metabolism ; Conserved Sequence ; Cysteine/genetics/metabolism ; Electric Conductivity ; Ion Transport/drug effects ; Models, Molecular ; Protein Conformation/drug effects ; Sodium-Potassium-Exchanging ATPase/antagonists & ; inhibitors/*chemistry/*metabolism ; Xenopus
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Publikationsdatum: 2008-05-27
    Beschreibung: Members of the epidermal growth factor receptor (EGFR) or ErbB/HER family and their activating ligands are essential regulators of diverse developmental processes. Inappropriate activation of these receptors is a key feature of many human cancers, and its reversal is an important clinical goal. A natural secreted antagonist of EGFR signalling, called Argos, was identified in Drosophila. We showed previously that Argos functions by directly binding (and sequestering) growth factor ligands that activate EGFR. Here we describe the 1.6-A resolution crystal structure of Argos bound to an EGFR ligand. Contrary to expectations, Argos contains no EGF-like domain. Instead, a trio of closely related domains (resembling a three-finger toxin fold) form a clamp-like structure around the bound EGF ligand. Although structurally unrelated to the receptor, Argos mimics EGFR by using a bipartite binding surface to entrap EGF. The individual Argos domains share unexpected structural similarities with the extracellular ligand-binding regions of transforming growth factor-beta family receptors. The three-domain clamp of Argos also resembles the urokinase-type plasminogen activator (uPA) receptor, which uses a similar mechanism to engulf the EGF-like module of uPA. Our results indicate that undiscovered mammalian counterparts of Argos may exist among other poorly characterized structural homologues. In addition, the structures presented here define requirements for the design of artificial EGF-sequestering proteins that would be valuable anti-cancer therapeutics.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2526102/" 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/PMC2526102/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Klein, Daryl E -- Stayrook, Steven E -- Shi, Fumin -- Narayan, Kartik -- Lemmon, Mark A -- R01 CA079992/CA/NCI NIH HHS/ -- R01 CA079992-10/CA/NCI NIH HHS/ -- R01 CA125432/CA/NCI NIH HHS/ -- R01 CA125432-01A1/CA/NCI NIH HHS/ -- England -- Nature. 2008 Jun 26;453(7199):1271-5. doi: 10.1038/nature06978. Epub 2008 May 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, 809C Stellar-Chance Laboratories, 422 Curie Boulevard, Philadelphia, Pennsylvania 19104-6059, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18500331" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding Sites ; Cell Line ; Crystallography, X-Ray ; Drosophila Proteins/*chemistry/*metabolism ; Drosophila melanogaster/*chemistry/cytology ; Epidermal Growth Factor/*chemistry/*metabolism ; Eye Proteins/*chemistry/*metabolism ; Humans ; Ligands ; Membrane Proteins/*chemistry/*metabolism ; Models, Molecular ; Nerve Tissue Proteins/*chemistry/*metabolism ; Protein Structure, Tertiary ; Receptor, Epidermal Growth Factor/antagonists & inhibitors/chemistry/*metabolism ; Receptors, Transforming Growth Factor beta/chemistry/metabolism ; Spodoptera
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 39
    Publikationsdatum: 2008-10-04
    Beschreibung: HIV-1 protease processes the Gag and Gag-Pol polyproteins into mature structural and functional proteins, including itself, and is therefore indispensable for viral maturation. The mature protease is active only as a dimer with each subunit contributing catalytic residues. The full-length transframe region protease precursor appears to be monomeric yet undergoes maturation via intramolecular cleavage of a putative precursor dimer, concomitant with the appearance of mature-like catalytic activity. How such intramolecular cleavage can occur when the amino and carboxy termini of the mature protease are part of an intersubunit beta-sheet located distal from the active site is unclear. Here we visualize the early events in N-terminal autoprocessing using an inactive mini-precursor with a four-residue N-terminal extension that mimics the transframe region protease precursor. Using paramagnetic relaxation enhancement, a technique that is exquisitely sensitive to the presence of minor species, we show that the mini-precursor forms highly transient, lowly populated (3-5%) dimeric encounter complexes that involve the mature dimer interface but occupy a wide range of subunit orientations relative to the mature dimer. Furthermore, the occupancy of the mature dimer configuration constitutes a very small fraction of the self-associated species (accounting for the very low enzymatic activity of the protease precursor), and the N-terminal extension makes transient intra- and intersubunit contacts with the substrate binding site and is therefore available for autocleavage when the correct dimer orientation is sampled within the encounter complex ensemble.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2798589/" 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/PMC2798589/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tang, Chun -- Louis, John M -- Aniana, Annie -- Suh, Jeong-Yong -- Clore, G Marius -- ZIA DK029023-19/Intramural NIH HHS/ -- England -- Nature. 2008 Oct 2;455(7213):693-6. doi: 10.1038/nature07342.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18833280" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Dimerization ; HIV Protease/*chemistry/genetics/*metabolism ; HIV-1/*enzymology/genetics ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Protein Precursors/*chemistry/genetics/*metabolism ; *Protein Processing, Post-Translational ; Protein Structure, Tertiary ; Spin Labels ; gag Gene Products, Human Immunodeficiency Virus/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 40
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    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-06-20
    Beschreibung: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2760068/" 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/PMC2760068/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brodsky, Barbara -- Baum, Jean -- R01 GM045302/GM/NIGMS NIH HHS/ -- R01 GM045302-14A2/GM/NIGMS NIH HHS/ -- R01 GM060048/GM/NIGMS NIH HHS/ -- R01 GM060048-29/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Jun 19;453(7198):998-9. doi: 10.1038/453998a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18563144" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Collagen Type I/*chemistry/*genetics/metabolism ; Humans ; Models, Molecular ; Molecular Sequence Data ; Osteogenesis Imperfecta/genetics/metabolism ; Peptides/chemistry/genetics/metabolism ; Structure-Activity Relationship
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Publikationsdatum: 2008-08-16
    Beschreibung: Non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) found in bacteria, fungi and plants use two different types of thioesterases for the production of highly active biological compounds. Type I thioesterases (TEI) catalyse the release step from the assembly line of the final product where it is transported from one reaction centre to the next as a thioester linked to a 4'-phosphopantetheine (4'-PP) cofactor that is covalently attached to thiolation (T) domains. The second enzyme involved in the synthesis of these secondary metabolites, the type II thioesterase (TEII), is a crucial repair enzyme for the regeneration of functional 4'-PP cofactors of holo-T domains of NRPS and PKS systems. Mispriming of 4'-PP cofactors by acetyl- and short-chain acyl-residues interrupts the biosynthetic system. This repair reaction is very important, because roughly 80% of CoA, the precursor of the 4'-PP cofactor, is acetylated in bacteria. Here we report the three-dimensional structure of a type II thioesterase from Bacillus subtilis free and in complex with a T domain. Comparison with structures of TEI enzymes shows the basis for substrate selectivity and the different modes of interaction of TEII and TEI enzymes with T domains. Furthermore, we show that the TEII enzyme exists in several conformations of which only one is selected on interaction with its native substrate, a modified holo-T domain.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2854587/" 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/PMC2854587/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Koglin, Alexander -- Lohr, Frank -- Bernhard, Frank -- Rogov, Vladimir V -- Frueh, Dominique P -- Strieter, Eric R -- Mofid, Mohammad R -- Guntert, Peter -- Wagner, Gerhard -- Walsh, Christopher T -- Marahiel, Mohamed A -- Dotsch, Volker -- P01 GM047467/GM/NIGMS NIH HHS/ -- P01 GM047467-110009/GM/NIGMS NIH HHS/ -- P01 GM047467-12/GM/NIGMS NIH HHS/ -- P01 GM047467-13/GM/NIGMS NIH HHS/ -- P01 GM047467-14/GM/NIGMS NIH HHS/ -- P01 GM047467-15/GM/NIGMS NIH HHS/ -- P01 GM047467-16/GM/NIGMS NIH HHS/ -- P01 GM047467-160010/GM/NIGMS NIH HHS/ -- P01 GM047467-160012/GM/NIGMS NIH HHS/ -- P01 GM047467-17/GM/NIGMS NIH HHS/ -- P01 GM047467-170012/GM/NIGMS NIH HHS/ -- P41 EB002026/EB/NIBIB NIH HHS/ -- P41 EB002026-29/EB/NIBIB NIH HHS/ -- P41 EB002026-30/EB/NIBIB NIH HHS/ -- P41 EB002026-31/EB/NIBIB NIH HHS/ -- P41 EB002026-32/EB/NIBIB NIH HHS/ -- P41 EB002026-33/EB/NIBIB NIH HHS/ -- R01 AI042738/AI/NIAID NIH HHS/ -- R01 AI042738-09/AI/NIAID NIH HHS/ -- R01 GM020011/GM/NIGMS NIH HHS/ -- R01 GM020011-28/GM/NIGMS NIH HHS/ -- R01 GM020011-29/GM/NIGMS NIH HHS/ -- R01 GM020011-30/GM/NIGMS NIH HHS/ -- R01 GM020011-31/GM/NIGMS NIH HHS/ -- R01 GM020011-32/GM/NIGMS NIH HHS/ -- R01 GM020011-37/GM/NIGMS NIH HHS/ -- R01 GM020011-38/GM/NIGMS NIH HHS/ -- R01 GM049338/GM/NIGMS NIH HHS/ -- R01 GM049338-17/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Aug 14;454(7206):907-11. doi: 10.1038/nature07161.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance and Cluster of Excellence Macromolecular Complexes (CEF), J.W.-Goethe University, 60438 Frankfurt am Main, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18704089" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacillus subtilis/*enzymology ; Bacterial Proteins/biosynthesis/*chemistry/*metabolism ; Fatty Acid Synthases/*chemistry/*metabolism ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Peptide Synthases/biosynthesis/*chemistry/*metabolism ; Protein Interaction Domains and Motifs ; Protein Structure, Tertiary ; Thiolester Hydrolases/*chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    Publikationsdatum: 2008-01-19
    Beschreibung: Spastin, the most common locus for mutations in hereditary spastic paraplegias, and katanin are related microtubule-severing AAA ATPases involved in constructing neuronal and non-centrosomal microtubule arrays and in segregating chromosomes. The mechanism by which spastin and katanin break and destabilize microtubules is unknown, in part owing to the lack of structural information on these enzymes. Here we report the X-ray crystal structure of the Drosophila spastin AAA domain and provide a model for the active spastin hexamer generated using small-angle X-ray scattering combined with atomic docking. The spastin hexamer forms a ring with a prominent central pore and six radiating arms that may dock onto the microtubule. Helices unique to the microtubule-severing AAA ATPases surround the entrances to the pore on either side of the ring, and three highly conserved loops line the pore lumen. Mutagenesis reveals essential roles for these structural elements in the severing reaction. Peptide and antibody inhibition experiments further show that spastin may dismantle microtubules by recognizing specific features in the carboxy-terminal tail of tubulin. Collectively, our data support a model in which spastin pulls the C terminus of tubulin through its central pore, generating a mechanical force that destabilizes tubulin-tubulin interactions within the microtubule lattice. Our work also provides insights into the structural defects in spastin that arise from mutations identified in hereditary spastic paraplegia patients.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2882799/" 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/PMC2882799/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Roll-Mecak, Antonina -- Vale, Ronald D -- K99 NS057934-01/NS/NINDS NIH HHS/ -- K99 NS057934-02/NS/NINDS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Jan 17;451(7176):363-7. doi: 10.1038/nature06482.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, 600 16th Street, San Francisco, California 94158, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18202664" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/antagonists & ; inhibitors/*chemistry/*genetics/*metabolism ; Animals ; Drosophila Proteins/antagonists & inhibitors/*chemistry/genetics/*metabolism ; Humans ; Microtubules/chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Scattering, Small Angle ; Spastic Paraplegia, Hereditary/*genetics ; Structure-Activity Relationship ; Substrate Specificity ; Tubulin/chemistry/metabolism ; X-Ray Diffraction
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    Publikationsdatum: 2008-05-02
    Beschreibung: Cytoplasmic polyhedrosis virus (CPV) is unique within the Reoviridae family in having a turreted single-layer capsid contained within polyhedrin inclusion bodies, yet being fully capable of cell entry and endogenous RNA transcription. Biochemical data have shown that the amino-terminal 79 residues of the CPV turret protein (TP) is sufficient to bring CPV or engineered proteins into the polyhedrin matrix for micro-encapsulation. Here we report the three-dimensional structure of CPV at 3.88 A resolution using single-particle cryo-electron microscopy. Our map clearly shows the turns and deep grooves of alpha-helices, the strand separation in beta-sheets, and densities for loops and many bulky side chains; thus permitting atomic model-building effort from cryo-electron microscopy maps. We observed a helix-to-beta-hairpin conformational change between the two conformational states of the capsid shell protein in the region directly interacting with genomic RNA. We have also discovered a messenger RNA release hole coupled with the mRNA capping machinery unique to CPV. Furthermore, we have identified the polyhedrin-binding domain, a structure that has potential in nanobiotechnology applications.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2746981/" 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/PMC2746981/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yu, Xuekui -- Jin, Lei -- Zhou, Z Hong -- P41 RR002250/RR/NCRR NIH HHS/ -- P41 RR002250-190043/RR/NCRR NIH HHS/ -- P41 RR002250-200043/RR/NCRR NIH HHS/ -- P41 RR002250-217385/RR/NCRR NIH HHS/ -- P41 RR002250-226489/RR/NCRR NIH HHS/ -- R01 AI069015/AI/NIAID NIH HHS/ -- R01 AI069015-01A1/AI/NIAID NIH HHS/ -- R01 AI069015-02/AI/NIAID NIH HHS/ -- R01 AI069015-03/AI/NIAID NIH HHS/ -- R01 GM071940/GM/NIGMS NIH HHS/ -- R01 GM071940-01A2/GM/NIGMS NIH HHS/ -- R01 GM071940-02/GM/NIGMS NIH HHS/ -- R01 GM071940-03/GM/NIGMS NIH HHS/ -- R01 GM071940-04/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 May 15;453(7193):415-9. doi: 10.1038/nature06893. Epub 2008 Apr 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology and Laboratory Medicine, The University of Texas Medical School at Houston, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18449192" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Bombyx/virology ; Capsid Proteins/chemistry/ultrastructure ; *Cryoelectron Microscopy ; Genome, Viral/physiology ; Larva/virology ; Models, Molecular ; RNA Caps/genetics/metabolism ; RNA Transport ; RNA, Viral/genetics/metabolism ; Reoviridae/chemistry/genetics/metabolism/*ultrastructure
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-05-24
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kowalczykowski, Stephen C -- R01 GM062653/GM/NIGMS NIH HHS/ -- R37 GM062653/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 May 22;453(7194):463-6. doi: 10.1038/453463a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18497811" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; *DNA Repair ; Models, Molecular ; Molecular Conformation ; Rec A Recombinases/*chemistry/*metabolism ; *Recombination, Genetic/genetics ; *Sequence Homology, Nucleic Acid
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    Publikationsdatum: 2008-05-03
    Beschreibung: During infection by Gram-negative pathogenic bacteria, the type III secretion system (T3SS) is assembled to allow for the direct transmission of bacterial virulence effectors into the host cell. The T3SS system is characterized by a series of prominent multi-component rings in the inner and outer bacterial membranes, as well as a translocation pore in the host cell membrane. These are all connected by a series of polymerized tubes that act as the direct conduit for the T3SS proteins to pass through to the host cell. During assembly of the T3SS, as well as the evolutionarily related flagellar apparatus, a post-translational cleavage event within the inner membrane proteins EscU/FlhB is required to promote a secretion-competent state. These proteins have long been proposed to act as a part of a molecular switch, which would regulate the appropriate chronological secretion of the various T3SS apparatus components during assembly and subsequently the transported virulence effectors. Here we show that a surface type II beta-turn in the Escherichia coli protein EscU undergoes auto-cleavage by a mechanism involving cyclization of a strictly conserved asparagine residue. Structural and in vivo analysis of point and deletion mutations illustrates the subtle conformational effects of auto-cleavage in modulating the molecular features of a highly conserved surface region of EscU, a potential point of interaction with other T3SS components at the inner membrane. In addition, this work provides new structural insight into the distinct conformational requirements for a large class of self-cleaving reactions involving asparagine cyclization.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zarivach, Raz -- Deng, Wanyin -- Vuckovic, Marija -- Felise, Heather B -- Nguyen, Hai V -- Miller, Samuel I -- Finlay, B Brett -- Strynadka, Natalie C J -- 5R01 AI030479/AI/NIAID NIH HHS/ -- R01 AI030479/AI/NIAID NIH HHS/ -- U54 AI057141/AI/NIAID NIH HHS/ -- England -- Nature. 2008 May 1;453(7191):124-7. doi: 10.1038/nature06832.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, and the Center for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18451864" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Asparagine/chemistry/metabolism ; Circular Dichroism ; Crystallography, X-Ray ; Cyclization ; Enteropathogenic Escherichia coli/*chemistry/*metabolism/pathogenicity ; Escherichia coli Proteins/*chemistry/genetics/*metabolism ; Models, Chemical ; Models, Molecular ; Protein Structure, Tertiary ; Salmonella typhimurium/genetics/metabolism ; Virulence Factors/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Publikationsdatum: 2008-12-05
    Beschreibung: Species-specific recognition between the egg extracellular matrix (zona pellucida) and sperm is the first, crucial step of mammalian fertilization. Zona pellucida filament components ZP3 and ZP2 act as sperm receptors, and mice lacking either of the corresponding genes produce oocytes without a zona pellucida and are completely infertile. Like their counterparts in the vitelline envelope of non-mammalian eggs and many other secreted eukaryotic proteins, zona pellucida subunits polymerize using a 'zona pellucida (ZP) domain' module, whose conserved amino-terminal part (ZP-N) was suggested to constitute a domain of its own. No atomic structure has been reported for ZP domain proteins, and there is no structural information on any conserved vertebrate protein that is essential for fertilization and directly involved in egg-sperm binding. Here we describe the 2.3 angstrom (A) resolution structure of the ZP-N fragment of mouse primary sperm receptor ZP3. The ZP-N fold defines a new immunoglobulin superfamily subtype with a beta-sheet extension characterized by an E' strand and an invariant tyrosine residue implicated in polymerization. The structure strongly supports the presence of ZP-N repeats within the N-terminal region of ZP2 and other vertebrate zona pellucida/vitelline envelope proteins, with implications for overall egg coat architecture, the post-fertilization block to polyspermy and speciation. Moreover, it provides an important framework for understanding human diseases caused by mutations in ZP domain proteins and developing new methods of non-hormonal contraception.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Monne, Magnus -- Han, Ling -- Schwend, Thomas -- Burendahl, Sofia -- Jovine, Luca -- G0500367/Medical Research Council/United Kingdom -- England -- Nature. 2008 Dec 4;456(7222):653-7. doi: 10.1038/nature07599.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Karolinska Institutet, Department of Biosciences and Nutrition, Halsovagen 7, SE-141 57 Huddinge, Sweden.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19052627" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Binding Sites ; CHO Cells ; Conserved Sequence ; Cricetinae ; Cricetulus ; Crystallization ; Crystallography, X-Ray ; Egg Proteins/*chemistry/genetics/*metabolism ; Female ; Male ; Membrane Glycoproteins/*chemistry/genetics/*metabolism ; Mice ; Models, Molecular ; Molecular Sequence Data ; Ovum/*chemistry/*metabolism ; Peptide Fragments/chemistry/genetics/metabolism ; Protein Folding ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Receptors, Cell Surface/*chemistry/genetics/*metabolism ; Repetitive Sequences, Amino Acid ; Spermatozoa/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    Publikationsdatum: 2008-03-21
    Beschreibung: The design of new enzymes for reactions not catalysed by naturally occurring biocatalysts is a challenge for protein engineering and is a critical test of our understanding of enzyme catalysis. Here we describe the computational design of eight enzymes that use two different catalytic motifs to catalyse the Kemp elimination-a model reaction for proton transfer from carbon-with measured rate enhancements of up to 10(5) and multiple turnovers. Mutational analysis confirms that catalysis depends on the computationally designed active sites, and a high-resolution crystal structure suggests that the designs have close to atomic accuracy. Application of in vitro evolution to enhance the computational designs produced a 〉200-fold increase in k(cat)/K(m) (k(cat)/K(m) of 2,600 M(-1)s(-1) and k(cat)/k(uncat) of 〉10(6)). These results demonstrate the power of combining computational protein design with directed evolution for creating new enzymes, and we anticipate the creation of a wide range of useful new catalysts in the future.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rothlisberger, Daniela -- Khersonsky, Olga -- Wollacott, Andrew M -- Jiang, Lin -- DeChancie, Jason -- Betker, Jamie -- Gallaher, Jasmine L -- Althoff, Eric A -- Zanghellini, Alexandre -- Dym, Orly -- Albeck, Shira -- Houk, Kendall N -- Tawfik, Dan S -- Baker, David -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 May 8;453(7192):190-5. doi: 10.1038/nature06879. Epub 2008 Mar 19.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18354394" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Algorithms ; Amino Acid Motifs ; Binding Sites/genetics ; Catalysis ; Computational Biology ; *Computer Simulation ; Crystallography, X-Ray ; Directed Molecular Evolution/*methods ; Drug Design ; Drug Evaluation, Preclinical ; Enzymes/*chemistry/genetics/*metabolism ; Kinetics ; Models, Chemical ; Models, Molecular ; Protein Engineering/*methods ; Quantum Theory ; Sensitivity and Specificity
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Publikationsdatum: 2008-05-23
    Beschreibung: All organisms have to monitor the folding state of cellular proteins precisely. The heat-shock protein DegP is a protein quality control factor in the bacterial envelope that is involved in eliminating misfolded proteins and in the biogenesis of outer-membrane proteins. Here we describe the molecular mechanisms underlying the regulated protease and chaperone function of DegP from Escherichia coli. We show that binding of misfolded proteins transforms hexameric DegP into large, catalytically active 12-meric and 24-meric multimers. A structural analysis of these particles revealed that DegP represents a protein packaging device whose central compartment is adaptable to the size and concentration of substrate. Moreover, the inner cavity serves antagonistic functions. Whereas the encapsulation of folded protomers of outer-membrane proteins is protective and might allow safe transit through the periplasm, misfolded proteins are eliminated in the molecular reaction chamber. Oligomer reassembly and concomitant activation on substrate binding may also be critical in regulating other HtrA proteases implicated in protein-folding diseases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Krojer, Tobias -- Sawa, Justyna -- Schafer, Eva -- Saibil, Helen R -- Ehrmann, Michael -- Clausen, Tim -- 070776/Wellcome Trust/United Kingdom -- 079605/Wellcome Trust/United Kingdom -- BB/C516144/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/C516179/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BB/F010281/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BBS/B/03955/Biotechnology and Biological Sciences Research Council/United Kingdom -- Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2008 Jun 12;453(7197):885-90. doi: 10.1038/nature07004. Epub 2008 May 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Research Institute for Molecular Pathology - IMP, Dr Bohrgasse 7, A-1030 Vienna, Austria.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18496527" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Outer Membrane ; Proteins/biosynthesis/chemistry/metabolism/ultrastructure ; Cell Membrane/metabolism ; Cryoelectron Microscopy ; Crystallography, X-Ray ; Escherichia coli/*enzymology ; Heat-Shock Proteins/*chemistry/*metabolism/ultrastructure ; Models, Molecular ; Molecular Chaperones/*chemistry/*metabolism/ultrastructure ; Periplasmic Proteins/*chemistry/*metabolism/ultrastructure ; Protein Folding ; Protein Structure, Quaternary ; Serine Endopeptidases/*chemistry/*metabolism/ultrastructure ; Structure-Activity Relationship
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Publikationsdatum: 2008-08-30
    Beschreibung: Neuroblastoma is a childhood cancer that can be inherited, but the genetic aetiology is largely unknown. Here we show that germline mutations in the anaplastic lymphoma kinase (ALK) gene explain most hereditary neuroblastomas, and that activating mutations can also be somatically acquired. We first identified a significant linkage signal at chromosome bands 2p23-24 using a whole-genome scan in neuroblastoma pedigrees. Resequencing of regional candidate genes identified three separate germline missense mutations in the tyrosine kinase domain of ALK that segregated with the disease in eight separate families. Resequencing in 194 high-risk neuroblastoma samples showed somatically acquired mutations in the tyrosine kinase domain in 12.4% of samples. Nine of the ten mutations map to critical regions of the kinase domain and were predicted, with high probability, to be oncogenic drivers. Mutations resulted in constitutive phosphorylation, and targeted knockdown of ALK messenger RNA resulted in profound inhibition of growth in all cell lines harbouring mutant or amplified ALK, as well as in two out of six wild-type cell lines for ALK. Our results demonstrate that heritable mutations of ALK are the main cause of familial neuroblastoma, and that germline or acquired activation of this cell-surface kinase is a tractable therapeutic target for this lethal paediatric malignancy.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672043/" 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/PMC2672043/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mosse, Yael P -- Laudenslager, Marci -- Longo, Luca -- Cole, Kristina A -- Wood, Andrew -- Attiyeh, Edward F -- Laquaglia, Michael J -- Sennett, Rachel -- Lynch, Jill E -- Perri, Patrizia -- Laureys, Genevieve -- Speleman, Frank -- Kim, Cecilia -- Hou, Cuiping -- Hakonarson, Hakon -- Torkamani, Ali -- Schork, Nicholas J -- Brodeur, Garrett M -- Tonini, Gian P -- Rappaport, Eric -- Devoto, Marcella -- Maris, John M -- K08 CA111733/CA/NCI NIH HHS/ -- K08 CA111733-04/CA/NCI NIH HHS/ -- K08-111733/PHS HHS/ -- R01 CA078545/CA/NCI NIH HHS/ -- R01 CA078545-09/CA/NCI NIH HHS/ -- R01 CA124709/CA/NCI NIH HHS/ -- R01-CA78454/CA/NCI NIH HHS/ -- R01-CA87847/CA/NCI NIH HHS/ -- U10 CA098543/CA/NCI NIH HHS/ -- U10 CA098543-06/CA/NCI NIH HHS/ -- England -- Nature. 2008 Oct 16;455(7215):930-5. doi: 10.1038/nature07261. Epub 2008 Aug 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18724359" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Base Sequence ; Cell Line, Tumor ; Child ; Chromosomes, Human, Pair 2/genetics ; Female ; Gene Dosage ; Gene Expression Regulation, Neoplastic ; Genetic Predisposition to Disease/*genetics ; Germ-Line Mutation/genetics ; Humans ; Male ; Models, Molecular ; Molecular Sequence Data ; Mutation/*genetics ; Neuroblastoma/*enzymology/*genetics ; Pedigree ; Phosphorylation ; Protein Structure, Tertiary ; Protein-Tyrosine Kinases/chemistry/deficiency/*genetics ; Receptor Protein-Tyrosine Kinases
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    Publikationsdatum: 2008-10-17
    Beschreibung: Most proteins are secreted from bacteria by the interaction of the cytoplasmic SecA ATPase with a membrane channel, formed by the heterotrimeric SecY complex. Here we report the crystal structure of SecA bound to the SecY complex, with a maximum resolution of 4.5 angstrom (A), obtained for components from Thermotoga maritima. One copy of SecA in an intermediate state of ATP hydrolysis is bound to one molecule of the SecY complex. Both partners undergo important conformational changes on interaction. The polypeptide-cross-linking domain of SecA makes a large conformational change that could capture the translocation substrate in a 'clamp'. Polypeptide movement through the SecY channel could be achieved by the motion of a 'two-helix finger' of SecA inside the cytoplasmic funnel of SecY, and by the coordinated tightening and widening of SecA's clamp above the SecY pore. SecA binding generates a 'window' at the lateral gate of the SecY channel and it displaces the plug domain, preparing the channel for signal sequence binding and channel opening.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zimmer, Jochen -- Nam, Yunsun -- Rapoport, Tom A -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Oct 16;455(7215):936-43. doi: 10.1038/nature07335.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18923516" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/*chemistry/*metabolism ; Adenosine Triphosphate/metabolism ; Bacillus subtilis/chemistry ; Bacterial Proteins/*chemistry/*metabolism ; Crystallography, X-Ray ; Hydrolysis ; Membrane Transport Proteins/*chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Movement ; Multiprotein Complexes/chemistry/metabolism ; Protein Binding ; Protein Conformation ; Protein Sorting Signals/physiology ; Protein Transport ; Structure-Activity Relationship ; Thermotoga maritima/*chemistry
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-05-16
    Beschreibung: Invertebrate phototransduction uses an inositol-1,4,5-trisphosphate signalling cascade in which photoactivated rhodopsin stimulates a G(q)-type G protein, that is, a class of G protein that stimulates membrane-bound phospholipase Cbeta. The same cascade is used by many G-protein-coupled receptors, indicating that invertebrate rhodopsin is a prototypical member. Here we report the crystal structure of squid (Todarodes pacificus) rhodopsin at 2.5 A resolution. Among seven transmembrane alpha-helices, helices V and VI extend into the cytoplasmic medium and, together with two cytoplasmic helices, they form a rigid protrusion from the membrane surface. This peculiar structure, which is not seen in bovine rhodopsin, seems to be crucial for the recognition of G(q)-type G proteins. The retinal Schiff base forms a hydrogen bond to Asn 87 or Tyr 111; it is far from the putative counterion Glu 180. In the crystal, a tight association is formed between the amino-terminal polypeptides of neighbouring monomers; this intermembrane dimerization may be responsible for the organization of hexagonally packed microvillar membranes in the photoreceptor rhabdom.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murakami, Midori -- Kouyama, Tsutomu -- England -- Nature. 2008 May 15;453(7193):363-7. doi: 10.1038/nature06925.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18480818" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Crystallography, X-Ray ; Decapodiformes/*chemistry ; Dimerization ; Models, Molecular ; Molecular Sequence Data ; Protein Structure, Secondary ; Retinaldehyde/metabolism ; Rhodopsin/*chemistry/metabolism ; Schiff Bases ; Vision, Ocular/physiology ; Water/chemistry/metabolism
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    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Publikationsdatum: 2008-07-25
    Beschreibung: Enterohaemorrhagic Escherichia coli attaches to the intestine through actin pedestals that are formed when the bacterium injects its protein EspF(U) (also known as TccP) into host cells. EspF(U) potently activates the host WASP (Wiskott-Aldrich syndrome protein) family of actin-nucleating factors, which are normally activated by the GTPase CDC42, among other signalling molecules. Apart from its amino-terminal type III secretion signal, EspF(U) consists of five-and-a-half 47-amino-acid repeats. Here we show that a 17-residue motif within this EspF(U) repeat is sufficient for interaction with N-WASP (also known as WASL). Unlike most pathogen proteins that interface with the cytoskeletal machinery, this motif does not mimic natural upstream activators: instead of mimicking an activated state of CDC42, EspF(U) mimics an autoinhibitory element found within N-WASP. Thus, EspF(U) activates N-WASP by competitively disrupting the autoinhibited state. By mimicking an internal regulatory element and not the natural activator, EspF(U) selectively activates only a precise subset of CDC42-activated processes. Although one repeat is able to stimulate actin polymerization, we show that multiple-repeat fragments have notably increased potency. The activities of these EspF(U) fragments correlate with their ability to coordinate activation of at least two N-WASP proteins. Thus, this pathogen has used a simple autoinhibitory fragment as a component to build a highly effective actin polymerization machine.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2749708/" 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/PMC2749708/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sallee, Nathan A -- Rivera, Gonzalo M -- Dueber, John E -- Vasilescu, Dan -- Mullins, R Dyche -- Mayer, Bruce J -- Lim, Wendell A -- PN2 EY016546/EY/NEI NIH HHS/ -- PN2 EY016546-05/EY/NEI NIH HHS/ -- R01 CA082258/CA/NCI NIH HHS/ -- R01 CA082258-10/CA/NCI NIH HHS/ -- R01 GM061010/GM/NIGMS NIH HHS/ -- R01 GM061010-09/GM/NIGMS NIH HHS/ -- R01 GM062583/GM/NIGMS NIH HHS/ -- R01 GM062583-07/GM/NIGMS NIH HHS/ -- U54 RR022232/RR/NCRR NIH HHS/ -- U54 RR022232-03/RR/NCRR NIH HHS/ -- U54 RR022232-03S1/RR/NCRR NIH HHS/ -- England -- Nature. 2008 Aug 21;454(7207):1005-8. doi: 10.1038/nature07170. Epub 2008 Jul 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, 600 16th Street, San Francisco, California 94158, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18650806" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Actins/chemistry/*metabolism ; Amino Acid Sequence ; Animals ; Carrier Proteins/chemistry/*metabolism ; Enterohemorrhagic Escherichia coli/*metabolism/pathogenicity ; Escherichia coli Proteins/chemistry/*metabolism ; Mice ; Models, Molecular ; *Molecular Mimicry ; Molecular Sequence Data ; NIH 3T3 Cells ; Protein Structure, Tertiary ; Repetitive Sequences, Nucleic Acid ; Signal Transduction/physiology ; Wiskott-Aldrich Syndrome Protein, Neuronal/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    Publikationsdatum: 2008-11-28
    Beschreibung: Gibberellins control a range of growth and developmental processes in higher plants and have been widely used in the agricultural industry. By binding to a nuclear receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins, including GIBBERELLIN INSENSITIVE (GAI). The precise manner in which GID1 discriminates and becomes activated by bioactive gibberellins for specific binding to DELLA proteins remains unclear. Here we present the crystal structure of a ternary complex of Arabidopsis thaliana GID1A, a bioactive gibberellin and the amino-terminal DELLA domain of GAI. In this complex, GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain containing DELLA, VHYNP and LExLE motifs. Our results establish a structural model of a plant hormone receptor that is distinct from the mechanism of the hormone perception and effector recognition of the known auxin receptors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murase, Kohji -- Hirano, Yoshinori -- Sun, Tai-ping -- Hakoshima, Toshio -- England -- Nature. 2008 Nov 27;456(7221):459-63. doi: 10.1038/nature07519.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19037309" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Arabidopsis/*chemistry/metabolism ; Arabidopsis Proteins/*chemistry/genetics/*metabolism ; Circular Dichroism ; Crystallography, X-Ray ; Gibberellins/metabolism/*pharmacology ; Models, Biological ; Models, Molecular ; Plant Growth Regulators/metabolism/*pharmacology ; Protein Binding ; Protein Structure, Tertiary/drug effects ; Receptors, Cell Surface/*chemistry/genetics/*metabolism ; Substrate Specificity
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    Publikationsdatum: 2008-11-21
    Beschreibung: Calpains are non-lysosomal calcium-dependent cysteine proteinases that selectively cleave proteins in response to calcium signals and thereby control cellular functions such as cytoskeletal remodelling, cell cycle progression, gene expression and apoptotic cell death. In mammals, the two best-characterized members of the calpain family, calpain 1 and calpain 2 (micro-calpain and m-calpain, respectively), are ubiquitously expressed. The activity of calpains is tightly controlled by the endogenous inhibitor calpastatin, which is an intrinsically unstructured protein capable of reversibly binding and inhibiting four molecules of calpain, but only in the presence of calcium. To date, the mechanism of inhibition by calpastatin and the basis for its absolute specificity have remained speculative. It was not clear how this unstructured protein inhibits calpains without being cleaved itself, nor was it known how calcium induced changes that facilitated the binding of calpastatin to calpain. Here we report the 2.4-A-resolution crystal structure of the calcium-bound calpain 2 heterodimer bound by one of the four inhibitory domains of calpastatin. Calpastatin is seen to inhibit calpain by occupying both sides of the active site cleft. Although the inhibitor passes through the active site cleft it escapes cleavage in a novel manner by looping out and around the active site cysteine. The inhibitory domain of calpastatin recognizes multiple lower affinity sites present only in the calcium-bound form of the enzyme, resulting in an interaction that is tight, specific and calcium dependent. This crystal structure, and that of a related complex, also reveal the conformational changes that calpain undergoes on binding calcium, which include opening of the active site cleft and movement of the domains relative to each other to produce a more compact enzyme.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hanna, Rachel A -- Campbell, Robert L -- Davies, Peter L -- England -- Nature. 2008 Nov 20;456(7220):409-12. doi: 10.1038/nature07451.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19020623" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Calcium/*metabolism ; Calcium-Binding Proteins/*chemistry/*metabolism ; Calpain/*antagonists & inhibitors/*chemistry/metabolism ; Catalytic Domain ; Crystallography, X-Ray ; Models, Molecular ; Protein Binding ; Protein Multimerization ; Rats ; Structure-Activity Relationship
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    Publikationsdatum: 2008-07-04
    Beschreibung: At termination of protein synthesis, type I release factors promote hydrolysis of the peptidyl-transfer RNA linkage in response to recognition of a stop codon. Here we describe the crystal structure of the Thermus thermophilus 70S ribosome in complex with the release factor RF1, tRNA and a messenger RNA containing a UAA stop codon, at 3.2 A resolution. The stop codon is recognized in a pocket formed by conserved elements of RF1, including its PxT recognition motif, and 16S ribosomal RNA. The codon and the 30S subunit A site undergo an induced fit that results in stabilization of a conformation of RF1 that promotes its interaction with the peptidyl transferase centre. Unexpectedly, the main-chain amide group of Gln 230 in the universally conserved GGQ motif of the factor is positioned to contribute directly to peptidyl-tRNA hydrolysis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Laurberg, Martin -- Asahara, Haruichi -- Korostelev, Andrei -- Zhu, Jianyu -- Trakhanov, Sergei -- Noller, Harry F -- England -- Nature. 2008 Aug 14;454(7206):852-7. doi: 10.1038/nature07115. Epub 2008 Jul 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California at Santa Cruz, Santa Cruz, California 95064, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18596689" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Codon, Terminator/genetics/metabolism ; Crystallography, X-Ray ; Models, Molecular ; *Peptide Chain Termination, Translational ; Peptide Termination Factors/chemistry/metabolism ; Peptidyl Transferases/chemistry/metabolism ; Protein Binding ; Protein Structure, Tertiary ; RNA, Bacterial/metabolism ; RNA, Ribosomal, 23S/chemistry ; RNA, Transfer/chemistry/genetics/metabolism ; Ribosomes/*chemistry/*metabolism ; Thermus thermophilus/*chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Publikationsdatum: 2008-10-25
    Beschreibung: Metals are needed by at least one-quarter of all proteins. Although metallochaperones insert the correct metal into some proteins, they have not been found for the vast majority, and the view is that most metalloproteins acquire their metals directly from cellular pools. However, some metals form more stable complexes with proteins than do others. For instance, as described in the Irving-Williams series, Cu(2+) and Zn(2+) typically form more stable complexes than Mn(2+). Thus it is unclear what cellular mechanisms manage metal acquisition by most nascent proteins. To investigate this question, we identified the most abundant Cu(2+)-protein, CucA (Cu(2+)-cupin A), and the most abundant Mn(2+)-protein, MncA (Mn(2+)-cupin A), in the periplasm of the cyanobacterium Synechocystis PCC 6803. Each of these newly identified proteins binds its respective metal via identical ligands within a cupin fold. Consistent with the Irving-Williams series, MncA only binds Mn(2+) after folding in solutions containing at least a 10(4) times molar excess of Mn(2+) over Cu(2+) or Zn(2+). However once MncA has bound Mn(2+), the metal does not exchange with Cu(2+). MncA and CucA have signal peptides for different export pathways into the periplasm, Tat and Sec respectively. Export by the Tat pathway allows MncA to fold in the cytoplasm, which contains only tightly bound copper or Zn(2+) (refs 10-12) but micromolar Mn(2+) (ref. 13). In contrast, CucA folds in the periplasm to acquire Cu(2+). These results reveal a mechanism whereby the compartment in which a protein folds overrides its binding preference to control its metal content. They explain why the cytoplasm must contain only tightly bound and buffered copper and Zn(2+).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tottey, Steve -- Waldron, Kevin J -- Firbank, Susan J -- Reale, Brian -- Bessant, Conrad -- Sato, Katsuko -- Cheek, Timothy R -- Gray, Joe -- Banfield, Mark J -- Dennison, Christopher -- Robinson, Nigel J -- BB/E001688/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BBS/B/02576/Biotechnology and Biological Sciences Research Council/United Kingdom -- G0500367/Medical Research Council/United Kingdom -- G0600759/Medical Research Council/United Kingdom -- England -- Nature. 2008 Oct 23;455(7216):1138-42. doi: 10.1038/nature07340.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle NE2 4HH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18948958" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Proteins/chemistry/isolation & purification/*metabolism ; Copper/metabolism ; Manganese/metabolism ; Metals, Heavy/*metabolism ; Models, Molecular ; Periplasm/metabolism ; Protein Binding ; *Protein Folding ; Protein Structure, Tertiary ; Synechocystis/metabolism ; Zinc/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Publikationsdatum: 2008-09-02
    Beschreibung: Deubiquitinating enzymes (DUBs) remove ubiquitin from conjugated substrates to regulate various cellular processes. The Zn(2+)-dependent DUBs AMSH and AMSH-LP regulate receptor trafficking by specifically cleaving Lys 63-linked polyubiquitin chains from internalized receptors. Here we report the crystal structures of the human AMSH-LP DUB domain alone and in complex with a Lys 63-linked di-ubiquitin at 1.2 A and 1.6 A resolutions, respectively. The AMSH-LP DUB domain consists of a Zn(2+)-coordinating catalytic core and two characteristic insertions, Ins-1 and Ins-2. The distal ubiquitin interacts with Ins-1 and the core, whereas the proximal ubiquitin interacts with Ins-2 and the core. The core and Ins-1 form a catalytic groove that accommodates the Lys 63 side chain of the proximal ubiquitin and the isopeptide-linked carboxy-terminal tail of the distal ubiquitin. This is the first reported structure of a DUB in complex with an isopeptide-linked ubiquitin chain, which reveals the mechanism for Lys 63-linkage-specific deubiquitination by AMSH family members.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sato, Yusuke -- Yoshikawa, Azusa -- Yamagata, Atsushi -- Mimura, Hisatoshi -- Yamashita, Masami -- Ookata, Kayoko -- Nureki, Osamu -- Iwai, Kazuhiro -- Komada, Masayuki -- Fukai, Shuya -- England -- Nature. 2008 Sep 18;455(7211):358-62. doi: 10.1038/nature07254. Epub 2008 Aug 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18758443" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Catalysis ; Conserved Sequence ; Crystallography, X-Ray ; Endopeptidases/chemistry/metabolism ; Endosomal Sorting Complexes Required for Transport ; Humans ; Kinetics ; Lysine/*metabolism ; Mice ; Models, Molecular ; Polyubiquitin/*chemistry/genetics/*metabolism ; Protein Structure, Tertiary ; Saccharomyces cerevisiae Proteins/chemistry/metabolism ; Structure-Activity Relationship ; Substrate Specificity ; Ubiquitin Thiolesterase/*chemistry/genetics/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Publikationsdatum: 2008-10-17
    Beschreibung: Over 30% of proteins are secreted across or integrated into membranes. Their newly synthesized forms contain either cleavable signal sequences or non-cleavable membrane anchor sequences, which direct them to the evolutionarily conserved Sec translocon (SecYEG in prokaryotes and Sec61, comprising alpha-, gamma- and beta-subunits, in eukaryotes). The translocon then functions as a protein-conducting channel. These processes of protein localization occur either at or after translation. In bacteria, the SecA ATPase drives post-translational translocation. The only high-resolution structure of a translocon available so far is that for SecYEbeta from the archaeon Methanococcus jannaschii, which lacks SecA. Here we present the 3.2-A-resolution crystal structure of the SecYE translocon from a SecA-containing organism, Thermus thermophilus. The structure, solved as a complex with an anti-SecY Fab fragment, revealed a 'pre-open' state of SecYE, in which several transmembrane helices are shifted, as compared to the previous SecYEbeta structure, to create a hydrophobic crack open to the cytoplasm. Fab and SecA bind to a common site at the tip of the cytoplasmic domain of SecY. Molecular dynamics and disulphide mapping analyses suggest that the pre-open state might represent a SecYE conformational transition that is inducible by SecA binding. Moreover, we identified a SecA-SecYE interface that comprises SecA residues originally buried inside the protein, indicating that both the channel and the motor components of the Sec machinery undergo cooperative conformational changes on formation of the functional complex.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2590585/" 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/PMC2590585/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tsukazaki, Tomoya -- Mori, Hiroyuki -- Fukai, Shuya -- Ishitani, Ryuichiro -- Mori, Takaharu -- Dohmae, Naoshi -- Perederina, Anna -- Sugita, Yuji -- Vassylyev, Dmitry G -- Ito, Koreaki -- Nureki, Osamu -- R01 GM074252/GM/NIGMS NIH HHS/ -- R01 GM074252-04/GM/NIGMS NIH HHS/ -- R01 GM074840/GM/NIGMS NIH HHS/ -- R01 GM074840-04/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Oct 16;455(7215):988-91. doi: 10.1038/nature07421.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18923527" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Proteins/*chemistry/genetics/immunology/*metabolism ; Binding Sites ; Crystallography, X-Ray ; Disulfides/chemistry/metabolism ; Hydrophobic and Hydrophilic Interactions ; Immunoglobulin Fab Fragments/chemistry/immunology ; Methanococcus/chemistry/enzymology ; Models, Biological ; Models, Molecular ; Protein Binding ; Protein Structure, Tertiary ; Thermus thermophilus/*chemistry/*enzymology/genetics
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Publikationsdatum: 2008-09-06
    Beschreibung: Maintenance methylation of hemimethylated CpG dinucleotides at DNA replication forks is the key to faithful mitotic inheritance of genomic methylation patterns. UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for maintenance methylation by interacting with DNA nucleotide methyltransferase 1 (DNMT1), the maintenance methyltransferase, and with hemimethylated CpG, the substrate for DNMT1 (refs 1 and 2). Here we present the crystal structure of the SET and RING-associated (SRA) domain of mouse UHRF1 in complex with DNA containing a hemimethylated CpG site. The DNA is contacted in both the major and minor grooves by two loops that penetrate into the middle of the DNA helix. The 5-methylcytosine has flipped completely out of the DNA helix and is positioned in a binding pocket with planar stacking contacts, Watson-Crick polar hydrogen bonds and van der Waals interactions specific for 5-methylcytosine. Hence, UHRF1 contains a previously unknown DNA-binding module and is the first example of a non-enzymatic, sequence-specific DNA-binding protein domain to use the base flipping mechanism to interact with DNA.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2602803/" 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/PMC2602803/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hashimoto, Hideharu -- Horton, John R -- Zhang, Xing -- Bostick, Magnolia -- Jacobsen, Steven E -- Cheng, Xiaodong -- CA1263022/CA/NCI NIH HHS/ -- GM049245/GM/NIGMS NIH HHS/ -- GM060398/GM/NIGMS NIH HHS/ -- R01 GM049245/GM/NIGMS NIH HHS/ -- R01 GM049245-15/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Oct 9;455(7214):826-9. doi: 10.1038/nature07280. Epub 2008 Sep 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18772888" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 5-Methylcytosine/*metabolism ; Animals ; Base Sequence ; CpG Islands/genetics ; Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; *DNA Methylation ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions ; Mice ; Models, Molecular ; Molecular Conformation ; Nuclear Proteins/*chemistry/*metabolism ; Protein Binding ; Protein Structure, Tertiary
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Publikationsdatum: 2008-10-31
    Beschreibung: AB(5) toxins comprise an A subunit that corrupts essential eukaryotic cell functions, and pentameric B subunits that direct target-cell uptake after binding surface glycans. Subtilase cytotoxin (SubAB) is an AB(5) toxin secreted by Shiga toxigenic Escherichia coli (STEC), which causes serious gastrointestinal disease in humans. SubAB causes haemolytic uraemic syndrome-like pathology in mice through SubA-mediated cleavage of BiP/GRP78, an essential endoplasmic reticulum chaperone. Here we show that SubB has a strong preference for glycans terminating in the sialic acid N-glycolylneuraminic acid (Neu5Gc), a monosaccharide not synthesized in humans. Structures of SubB-Neu5Gc complexes revealed the basis for this specificity, and mutagenesis of key SubB residues abrogated in vitro glycan recognition, cell binding and cytotoxicity. SubAB specificity for Neu5Gc was confirmed using mouse tissues with a human-like deficiency of Neu5Gc and human cell lines fed with Neu5Gc. Despite lack of Neu5Gc biosynthesis in humans, assimilation of dietary Neu5Gc creates high-affinity receptors on human gut epithelia and kidney vasculature. This, and the lack of Neu5Gc-containing body fluid competitors in humans, confers susceptibility to the gastrointestinal and systemic toxicities of SubAB. Ironically, foods rich in Neu5Gc are the most common source of STEC contamination. Thus a bacterial toxin's receptor is generated by metabolic incorporation of an exogenous factor derived from food.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2723748/" 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/PMC2723748/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Byres, Emma -- Paton, Adrienne W -- Paton, James C -- Lofling, Jonas C -- Smith, David F -- Wilce, Matthew C J -- Talbot, Ursula M -- Chong, Damien C -- Yu, Hai -- Huang, Shengshu -- Chen, Xi -- Varki, Nissi M -- Varki, Ajit -- Rossjohn, Jamie -- Beddoe, Travis -- R01 AI068715-01A1/AI/NIAID NIH HHS/ -- R01 AI068715-02/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Dec 4;456(7222):648-52. doi: 10.1038/nature07428. Epub 2008 Oct 29.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Protein Crystallography Unit and ARC Centre of Excellence for Structural and Functional Microbial Genomics, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18971931" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Bacterial Toxins/chemistry/genetics/*metabolism/*toxicity ; Cell Death/drug effects ; Cell Line ; Crystallography, X-Ray ; Escherichia coli Proteins/*chemistry/genetics/metabolism/*toxicity ; Humans ; Mice ; Microscopy, Fluorescence ; Models, Molecular ; Neuraminic Acids/administration & dosage/*metabolism/pharmacology ; Polysaccharides/*chemistry/*metabolism ; Protein Binding ; Protein Subunits ; Shiga-Toxigenic Escherichia coli/chemistry/pathogenicity ; Sialic Acids/chemistry/metabolism ; Species Specificity ; Substrate Specificity ; Subtilisins/*chemistry/genetics/metabolism/*toxicity ; Survival Analysis
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Publikationsdatum: 2008-09-27
    Beschreibung: Opsin, the ligand-free form of the G-protein-coupled receptor rhodopsin, at low pH adopts a conformationally distinct, active G-protein-binding state known as Ops*. A synthetic peptide derived from the main binding site of the heterotrimeric G protein-the carboxy terminus of the alpha-subunit (GalphaCT)-stabilizes Ops*. Here we present the 3.2 A crystal structure of the bovine Ops*-GalphaCT peptide complex. GalphaCT binds to a site in opsin that is opened by an outward tilt of transmembrane helix (TM) 6, a pairing of TM5 and TM6, and a restructured TM7-helix 8 kink. Contacts along the inner surface of TM5 and TM6 induce an alpha-helical conformation in GalphaCT with a C-terminal reverse turn. Main-chain carbonyl groups in the reverse turn constitute the centre of a hydrogen-bonded network, which links the two receptor regions containing the conserved E(D)RY and NPxxY(x)(5,6)F motifs. On the basis of the Ops*-GalphaCT structure and known conformational changes in Galpha, we discuss signal transfer from the receptor to the G protein nucleotide-binding site.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Scheerer, Patrick -- Park, Jung Hee -- Hildebrand, Peter W -- Kim, Yong Ju -- Krauss, Norbert -- Choe, Hui-Woog -- Hofmann, Klaus Peter -- Ernst, Oliver P -- England -- Nature. 2008 Sep 25;455(7212):497-502. doi: 10.1038/nature07330.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Medizinische Physik und Biophysik (CC2), Charite - Universitatsmedizin Berlin, Chariteplatz 1, D-10117 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18818650" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Animals ; Arginine/chemistry/metabolism ; Binding Sites ; Cattle ; Conserved Sequence ; Crystallization ; Crystallography, X-Ray ; GTP-Binding Protein alpha Subunits/*chemistry/*metabolism ; Models, Biological ; Models, Molecular ; Protein Conformation ; Regeneration ; Retinaldehyde/chemistry/metabolism ; Rhodopsin/chemistry ; Rod Opsins/*chemistry/*metabolism ; Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    facet.materialart.
    Unbekannt
    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-05-16
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schertler, Gebhard F X -- MC_U105178937/Medical Research Council/United Kingdom -- England -- Nature. 2008 May 15;453(7193):292-3. doi: 10.1038/453292a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18480801" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Crystallography, X-Ray ; Decapodiformes/*chemistry ; Models, Molecular ; Protein Structure, Secondary ; Rhodopsin/*chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Publikationsdatum: 2008-09-12
    Beschreibung: Rapidly growing cells produce thousands of new ribosomes each minute, in a tightly regulated process that is essential to cell growth. How the Escherichia coli 16S ribosomal RNA and the 20 proteins that make up the 30S ribosomal subunit can assemble correctly in a few minutes remains a challenging problem, partly because of the lack of real-time data on the earliest stages of assembly. By providing snapshots of individual RNA and protein interactions as they emerge in real time, here we show that 30S assembly nucleates concurrently from different points along the rRNA. Time-resolved hydroxyl radical footprinting was used to map changes in the structure of the rRNA within 20 milliseconds after the addition of total 30S proteins. Helical junctions in each domain fold within 100 ms. In contrast, interactions surrounding the decoding site and between the 5', the central and the 3' domains require 2-200 seconds to form. Unexpectedly, nucleotides contacted by the same protein are protected at different rates, indicating that initial RNA-protein encounter complexes refold during assembly. Although early steps in assembly are linked to intrinsically stable rRNA structure, later steps correspond to regions of induced fit between the proteins and the rRNA.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2720798/" 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/PMC2720798/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Adilakshmi, Tadepalli -- Bellur, Deepti L -- Woodson, Sarah A -- GM60819/GM/NIGMS NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- P41-EB0001979/EB/NIBIB NIH HHS/ -- R01 GM060819/GM/NIGMS NIH HHS/ -- R01 GM060819-10/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Oct 30;455(7217):1268-72. doi: 10.1038/nature07298. Epub 2008 Sep 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218-2685, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18784650" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Escherichia coli/chemistry/*genetics/*metabolism ; Kinetics ; Models, Molecular ; *Nucleic Acid Conformation ; Protein Binding ; Protein Conformation ; RNA, Ribosomal, 16S/*genetics/*metabolism ; Ribosomal Proteins/chemistry/genetics/metabolism ; Ribosomes/chemistry/*genetics/*metabolism ; Synchrotrons ; X-Rays
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    Publikationsdatum: 2008-10-17
    Beschreibung: An important step in the biosynthesis of many proteins is their partial or complete translocation across the plasma membrane in prokaryotes or the endoplasmic reticulum membrane in eukaryotes. In bacteria, secretory proteins are generally translocated after completion of their synthesis by the interaction of the cytoplasmic ATPase SecA and a protein-conducting channel formed by the SecY complex. How SecA moves substrates through the SecY channel is unclear. However, a recent structure of a SecA-SecY complex raises the possibility that the polypeptide chain is moved by a two-helix finger domain of SecA that is inserted into the cytoplasmic opening of the SecY channel. Here we have used disulphide-bridge crosslinking to show that the loop at the tip of the two-helix finger of Escherichia coli SecA interacts with a polypeptide chain right at the entrance into the SecY pore. Mutagenesis demonstrates that a tyrosine in the loop is particularly important for translocation, but can be replaced by some other bulky, hydrophobic residues. We propose that the two-helix finger of SecA moves a polypeptide chain into the SecY channel with the tyrosine providing the major contact with the substrate, a mechanism analogous to that suggested for hexameric, protein-translocating ATPases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4354775/" 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/PMC4354775/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Erlandson, Karl J -- Miller, Stephanie B M -- Nam, Yunsun -- Osborne, Andrew R -- Zimmer, Jochen -- Rapoport, Tom A -- R01 GM052586/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Oct 16;455(7215):984-7. doi: 10.1038/nature07439.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18923526" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/*chemistry/genetics/*metabolism ; Amino Acid Motifs ; Bacterial Proteins/*chemistry/genetics/*metabolism ; Cross-Linking Reagents ; Disulfides/chemistry/metabolism ; Escherichia coli/*enzymology ; Escherichia coli Proteins/chemistry/metabolism ; Membrane Transport Proteins/*chemistry/genetics/*metabolism ; Models, Biological ; Models, Molecular ; Protein Conformation ; Protein Transport ; Structure-Activity Relationship ; Tyrosine/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    Publikationsdatum: 2008-08-22
    Beschreibung: The oxylipin pathway generates not only prostaglandin-like jasmonates but also green leaf volatiles (GLVs), which confer characteristic aromas to fruits and vegetables. Although allene oxide synthase (AOS) and hydroperoxide lyase are atypical cytochrome P450 family members involved in the synthesis of jasmonates and GLVs, respectively, it is unknown how these enzymes rearrange their hydroperoxide substrates into different products. Here we present the crystal structures of Arabidopsis thaliana AOS, free and in complex with substrate or intermediate analogues. The structures reveal an unusual active site poised to control the reactivity of an epoxyallylic radical and its cation by means of interactions with an aromatic pi-system. Replacing the amino acid involved in these steps by a non-polar residue markedly reduces AOS activity and, unexpectedly, is both necessary and sufficient for converting AOS into a GLV biosynthetic enzyme. Furthermore, by combining our structural data with bioinformatic and biochemical analyses, we have discovered previously unknown hydroperoxide lyase in plant growth-promoting rhizobacteria, AOS in coral, and epoxyalcohol synthase in amphioxus. These results indicate that oxylipin biosynthetic genes were present in the last common ancestor of plants and animals, but were subsequently lost in all metazoan lineages except Placozoa, Cnidaria and Cephalochordata.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, Dong-Sun -- Nioche, Pierre -- Hamberg, Mats -- Raman, C S -- R01 AI054444/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Sep 18;455(7211):363-8. doi: 10.1038/nature07307. Epub 2008 Aug 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18716621" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Arabidopsis/enzymology/genetics ; Binding Sites ; Catalysis ; Cytochrome P-450 Enzyme System/chemistry/metabolism ; *Evolution, Molecular ; Intramolecular Oxidoreductases/*chemistry/genetics/*metabolism ; Models, Chemical ; Models, Molecular ; Molecular Sequence Data ; Oxylipins/*metabolism ; Point Mutation/genetics ; Protein Conformation
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Publikationsdatum: 2008-07-11
    Beschreibung: Ebola virus (EBOV) entry requires the surface glycoprotein (GP) to initiate attachment and fusion of viral and host membranes. Here we report the crystal structure of EBOV GP in its trimeric, pre-fusion conformation (GP1+GP2) bound to a neutralizing antibody, KZ52, derived from a human survivor of the 1995 Kikwit outbreak. Three GP1 viral attachment subunits assemble to form a chalice, cradled by the GP2 fusion subunits, while a novel glycan cap and projected mucin-like domain restrict access to the conserved receptor-binding site sequestered in the chalice bowl. The glycocalyx surrounding GP is likely central to immune evasion and may explain why survivors have insignificant neutralizing antibody titres. KZ52 recognizes a protein epitope at the chalice base where it clamps several regions of the pre-fusion GP2 to the amino terminus of GP1. This structure provides a template for unravelling the mechanism of EBOV GP-mediated fusion and for future immunotherapeutic development.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2700032/" 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/PMC2700032/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, Jeffrey E -- Fusco, Marnie L -- Hessell, Ann J -- Oswald, Wendelien B -- Burton, Dennis R -- Saphire, Erica Ollmann -- R01 AI067927/AI/NIAID NIH HHS/ -- R01 AI067927-03/AI/NIAID NIH HHS/ -- R21 AI053423/AI/NIAID NIH HHS/ -- R21 AI053423-02/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Jul 10;454(7201):177-82. doi: 10.1038/nature07082.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, Mail Drop IMM-2, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18615077" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antibodies, Viral/genetics/*immunology ; Binding Sites, Antibody ; Cathepsins/metabolism ; Cell Line ; Cricetinae ; Cricetulus ; Crystallography, X-Ray ; Democratic Republic of the Congo ; Ebolavirus/*chemistry/immunology ; Glycoproteins/*chemistry/*immunology/metabolism ; Glycosylation ; Humans ; Membrane Fusion ; Models, Molecular ; Protein Conformation ; Receptors, Virus/chemistry/metabolism ; *Survivors
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 67
    Publikationsdatum: 2008-07-11
    Beschreibung: The recent emergence of highly pathogenic avian influenza A virus strains with subtype H5N1 pose a global threat to human health. Elucidation of the underlying mechanisms of viral replication is critical for development of anti-influenza virus drugs. The influenza RNA-dependent RNA polymerase (RdRp) heterotrimer has crucial roles in viral RNA replication and transcription. It contains three proteins: PA, PB1 and PB2. PB1 harbours polymerase and endonuclease activities and PB2 is responsible for cap binding; PA is implicated in RNA replication and proteolytic activity, although its function is less clearly defined. Here we report the 2.9 angstrom structure of avian H5N1 influenza A virus PA (PA(C), residues 257-716) in complex with the PA-binding region of PB1 (PB1(N), residues 1-25). PA(C) has a fold resembling a dragon's head with PB1(N) clamped into its open 'jaws'. PB1(N) is a known inhibitor that blocks assembly of the polymerase heterotrimer and abolishes viral replication. Our structure provides details for the binding of PB1(N) to PA(C) at the atomic level, demonstrating a potential target for novel anti-influenza therapeutics. We also discuss a potential nucleotide binding site and the roles of some known residues involved in polymerase activity. Furthermore, to explore the role of PA in viral replication and transcription, we propose a model for the influenza RdRp heterotrimer by comparing PA(C) with the lambda3 reovirus polymerase structure, and docking the PA(C) structure into an available low resolution electron microscopy map.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉He, Xiaojing -- Zhou, Jie -- Bartlam, Mark -- Zhang, Rongguang -- Ma, Jianyuan -- Lou, Zhiyong -- Li, Xuemei -- Li, Jingjing -- Joachimiak, Andrzej -- Zeng, Zonghao -- Ge, Ruowen -- Rao, Zihe -- Liu, Yingfang -- England -- Nature. 2008 Aug 28;454(7208):1123-6. doi: 10.1038/nature07120. Epub 2008 Jul 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18615018" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding Sites ; Birds/*virology ; Crystallography, X-Ray ; Influenza A Virus, H5N1 Subtype/*enzymology ; Models, Molecular ; Multienzyme Complexes/chemistry/metabolism ; Nucleotides/metabolism ; Peptide Fragments/chemistry/metabolism ; Protein Binding ; Protein Structure, Quaternary ; RNA Replicase/*chemistry/metabolism ; Viral Proteins/*chemistry/*metabolism ; Virus Replication
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    Publikationsdatum: 2008-08-16
    Beschreibung: Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane. Additional mechanisms, such as directed transport or coupled inhibitors, have been proposed to be required for reinforcing a unique axis of polarity. Here we analyse a simple model of positive feedback, with strong analogy to the 'stepping stone' model of population genetics, in which a single species of diffusible, membrane-bound signalling molecules can self-recruit from a cytoplasmic pool. We identify an intrinsic stochastic mechanism through which positive feedback alone is sufficient to account for the spontaneous establishment of a single site of polarity. We find that the polarization frequency has an inverse dependence on the number of signalling molecules: the frequency of polarization decreases as the number of molecules becomes large. Experimental observation of polarizing Cdc42 in budding yeast is consistent with this prediction. Our work suggests that positive feedback can work alone or with additional mechanisms to create robust cell polarity.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562338/" 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/PMC2562338/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Altschuler, Steven J -- Angenent, Sigurd B -- Wang, Yanqin -- Wu, Lani F -- R01 GM071794/GM/NIGMS NIH HHS/ -- R01 GM071794-05/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Aug 14;454(7206):886-9. doi: 10.1038/nature07119.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Green Center for Systems Biology, Department of Pharmacology and Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA. steven.altschuler@utsouthwestern.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18704086" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Cell Polarity/*physiology ; Computer Simulation ; Feedback, Physiological ; Models, Biological ; Models, Molecular ; Saccharomyces cerevisiae/*cytology/*metabolism ; Signal Transduction ; cdc42 GTP-Binding Protein, Saccharomyces cerevisiae/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Publikationsdatum: 2008-12-02
    Beschreibung: Nuclear receptors are multi-domain transcription factors that bind to DNA elements from which they regulate gene expression. The peroxisome proliferator-activated receptors (PPARs) form heterodimers with the retinoid X receptor (RXR), and PPAR-gamma has been intensively studied as a drug target because of its link to insulin sensitization. Previous structural studies have focused on isolated DNA or ligand-binding segments, with no demonstration of how multiple domains cooperate to modulate receptor properties. Here we present structures of intact PPAR-gamma and RXR-alpha as a heterodimer bound to DNA, ligands and coactivator peptides. PPAR-gamma and RXR-alpha form a non-symmetric complex, allowing the ligand-binding domain (LBD) of PPAR-gamma to contact multiple domains in both proteins. Three interfaces link PPAR-gamma and RXR-alpha, including some that are DNA dependent. The PPAR-gamma LBD cooperates with both DNA-binding domains (DBDs) to enhance response-element binding. The A/B segments are highly dynamic, lacking folded substructures despite their gene-activation properties.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2743566/" 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/PMC2743566/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chandra, Vikas -- Huang, Pengxiang -- Hamuro, Yoshitomo -- Raghuram, Srilatha -- Wang, Yongjun -- Burris, Thomas P -- Rastinejad, Fraydoon -- R01 GM055217/GM/NIGMS NIH HHS/ -- R01 GM055217-11/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Nov 20;456(7220):350-6. doi: 10.1038/nature07413.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, and Center for Molecular Design, University of Virginia Health System, 1300 Jefferson Park Avenue, Charlottesville, Virginia 22908-0735, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19043829" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Allosteric Regulation ; Base Sequence ; DNA/chemistry/genetics/*metabolism ; Humans ; Ligands ; Models, Molecular ; Multiprotein Complexes/*chemistry/*metabolism ; PPAR gamma/*chemistry/*metabolism ; Protein Binding ; Protein Multimerization ; Protein Structure, Tertiary ; Response Elements/genetics ; Retinoid X Receptor alpha/*chemistry/*metabolism
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  • 70
    Publikationsdatum: 2008-02-01
    Beschreibung: The integral membrane protein M2 of influenza virus forms pH-gated proton channels in the viral lipid envelope. The low pH of an endosome activates the M2 channel before haemagglutinin-mediated fusion. Conductance of protons acidifies the viral interior and thereby facilitates dissociation of the matrix protein from the viral nucleoproteins--a required process for unpacking of the viral genome. In addition to its role in release of viral nucleoproteins, M2 in the trans-Golgi network (TGN) membrane prevents premature conformational rearrangement of newly synthesized haemagglutinin during transport to the cell surface by equilibrating the pH of the TGN with that of the host cell cytoplasm. Inhibiting the proton conductance of M2 using the anti-viral drug amantadine or rimantadine inhibits viral replication. Here we present the structure of the tetrameric M2 channel in complex with rimantadine, determined by NMR. In the closed state, four tightly packed transmembrane helices define a narrow channel, in which a 'tryptophan gate' is locked by intermolecular interactions with aspartic acid. A carboxy-terminal, amphipathic helix oriented nearly perpendicular to the transmembrane helix forms an inward-facing base. Lowering the pH destabilizes the transmembrane helical packing and unlocks the gate, admitting water to conduct protons, whereas the C-terminal base remains intact, preventing dissociation of the tetramer. Rimantadine binds at four equivalent sites near the gate on the lipid-facing side of the channel and stabilizes the closed conformation of the pore. Drug-resistance mutations are predicted to counter the effect of drug binding by either increasing the hydrophilicity of the pore or weakening helix-helix packing, thus facilitating channel opening.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3108054/" 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/PMC3108054/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schnell, Jason R -- Chou, James J -- R01 AI067438/AI/NIAID NIH HHS/ -- R01 AI067438-01A1/AI/NIAID NIH HHS/ -- R01 AI067438-02/AI/NIAID NIH HHS/ -- R01 AI067438-03/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Jan 31;451(7178):591-5. doi: 10.1038/nature06531.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18235503" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Aspartic Acid/metabolism ; Disulfides/metabolism ; Drug Resistance, Viral/genetics ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions ; Influenza A virus/*chemistry/genetics/metabolism ; Ion Channel Gating/drug effects ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Protein Structure, Quaternary ; Protein Structure, Secondary ; Protons ; Rimantadine/chemistry/metabolism/pharmacology ; Structure-Activity Relationship ; Tryptophan/metabolism ; Viral Matrix Proteins/*chemistry/genetics/*metabolism ; Water/metabolism
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  • 71
    Publikationsdatum: 2008-09-06
    Beschreibung: DNA methylation of CpG dinucleotides is an important epigenetic modification of mammalian genomes and is essential for the regulation of chromatin structure, of gene expression and of genome stability. Differences in DNA methylation patterns underlie a wide range of biological processes, such as genomic imprinting, inactivation of the X chromosome, embryogenesis, and carcinogenesis. Inheritance of the epigenetic methylation pattern is mediated by the enzyme DNA methyltransferase 1 (Dnmt1), which methylates newly synthesized CpG sequences during DNA replication, depending on the methylation status of the template strands. The protein UHRF1 (also known as Np95 and ICBP90) recognizes hemi-methylation sites via a SET and RING-associated (SRA) domain and directs Dnmt1 to these sites. Here we report the crystal structures of the SRA domain in free and hemi-methylated DNA-bound states. The SRA domain folds into a globular structure with a basic concave surface formed by highly conserved residues. Binding of DNA to the concave surface causes a loop and an amino-terminal tail of the SRA domain to fold into DNA interfaces at the major and minor grooves of the methylation site. In contrast to fully methylated CpG sites recognized by the methyl-CpG-binding domain, the methylcytosine base at the hemi-methylated site is flipped out of the DNA helix in the SRA-DNA complex and fits tightly into a protein pocket on the concave surface. The complex structure suggests that the successive flip out of the pre-existing methylated cytosine and the target cytosine to be methylated is associated with the coordinated transfer of the hemi-methylated CpG site from UHRF1 to Dnmt1.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Arita, Kyohei -- Ariyoshi, Mariko -- Tochio, Hidehito -- Nakamura, Yusuke -- Shirakawa, Masahiro -- England -- Nature. 2008 Oct 9;455(7214):818-21. doi: 10.1038/nature07249. Epub 2008 Sep 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18772891" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 5-Methylcytosine/metabolism ; Animals ; Base Sequence ; Conserved Sequence ; CpG Islands/genetics ; Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; DNA (Cytosine-5-)-Methyltransferase/metabolism ; *DNA Methylation ; Mice ; Models, Biological ; Models, Molecular ; Molecular Conformation ; Nuclear Proteins/*chemistry/*metabolism ; Protein Binding ; Protein Structure, Tertiary
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  • 72
    Publikationsdatum: 2008-05-24
    Beschreibung: Targeted protein degradation is largely performed by the ubiquitin-proteasome pathway, in which substrate proteins are marked by covalently attached ubiquitin chains that mediate recognition by the proteasome. It is currently unclear how the proteasome recognizes its substrates, as the only established ubiquitin receptor intrinsic to the proteasome is Rpn10/S5a (ref. 1), which is not essential for ubiquitin-mediated protein degradation in budding yeast. In the accompanying manuscript we report that Rpn13 (refs 3-7), a component of the nine-subunit proteasome base, functions as a ubiquitin receptor, complementing its known role in docking de-ubiquitinating enzyme Uch37/UCHL5 (refs 4-6) to the proteasome. Here we merge crystallography and NMR data to describe the ubiquitin-binding mechanism of Rpn13. We determine the structure of Rpn13 alone and complexed with ubiquitin. The co-complex reveals a novel ubiquitin-binding mode in which loops rather than secondary structural elements are used to capture ubiquitin. Further support for the role of Rpn13 as a proteasomal ubiquitin receptor is demonstrated by its ability to bind ubiquitin and proteasome subunit Rpn2/S1 simultaneously. Finally, we provide a model structure of Rpn13 complexed to diubiquitin, which provides insights into how Rpn13 as a ubiquitin receptor is coupled to substrate deubiquitination by Uch37.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2825158/" 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/PMC2825158/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schreiner, Patrick -- Chen, Xiang -- Husnjak, Koraljka -- Randles, Leah -- Zhang, Naixia -- Elsasser, Suzanne -- Finley, Daniel -- Dikic, Ivan -- Walters, Kylie J -- Groll, Michael -- CA097004/CA/NCI NIH HHS/ -- GM008700/GM/NIGMS NIH HHS/ -- GM43601/GM/NIGMS NIH HHS/ -- R01 CA097004/CA/NCI NIH HHS/ -- R01 CA097004-05/CA/NCI NIH HHS/ -- R01 CA097004-06A1/CA/NCI NIH HHS/ -- R37 GM043601/GM/NIGMS NIH HHS/ -- R37 GM043601-17/GM/NIGMS NIH HHS/ -- T32 GM008700/GM/NIGMS NIH HHS/ -- T32 GM008700-09/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 May 22;453(7194):548-52. doi: 10.1038/nature06924.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Integrated Protein Science at the Department Chemie, Lehrstuhl fur Biochemie, Technische Universitat Munchen, Lichtenbergstrasse 4, D-85747 Garching, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18497827" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Motifs ; Animals ; Cell Adhesion Molecules/*chemistry/genetics/*metabolism ; Crystallography, X-Ray ; Humans ; Membrane Glycoproteins/chemistry/genetics/metabolism ; Mice ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Proteasome Endopeptidase Complex/*chemistry/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Protein Subunits/chemistry/genetics/metabolism ; Ubiquitin/chemistry/*metabolism
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  • 73
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    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-05-10
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Arnold, Eddy -- Sarafianos, Stefan G -- England -- Nature. 2008 May 8;453(7192):169-70. doi: 10.1038/453169b.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18464731" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Catalysis ; DNA Primers/genetics/metabolism ; *DNA Replication ; HIV/*enzymology/genetics ; HIV Reverse Transcriptase/*chemistry/*metabolism ; Ligands ; Models, Molecular ; RNA/genetics/*metabolism ; *Reverse Transcription ; Substrate Specificity ; Templates, Genetic
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  • 74
    Publikationsdatum: 2008-03-07
    Beschreibung: Pentameric ligand-gated ion channels (pLGICs) are key players in the early events of electrical signal transduction at chemical synapses. The family codes for a structurally conserved scaffold of channel proteins that open in response to the binding of neurotransmitter molecules. All proteins share a pentameric organization of identical or related subunits that consist of an extracellular ligand-binding domain followed by a transmembrane channel domain. The nicotinic acetylcholine receptor (nAChR) is the most thoroughly studied member of the pLGIC family (for recent reviews see refs 1-3). Two sources of structural information provided an architectural framework for the family. The structure of the soluble acetylcholine-binding protein (AChBP) defined the organization of the extracellular domain and revealed the chemical basis of ligand interaction. Electron microscopy studies of the nAChR from Torpedo electric ray have yielded a picture of the full-length protein and have recently led to the interpretation of an electron density map at 4.0 A resolution. Despite the wealth of experimental information, high-resolution structures of any family member have so far not been available. Until recently, the pLGICs were believed to be only expressed in multicellular eukaryotic organisms. The abundance of prokaryotic genome sequences, however, allowed the identification of several homologous proteins in bacterial sources. Here we present the X-ray structure of a prokaryotic pLGIC from the bacterium Erwinia chrysanthemi (ELIC) at 3.3 A resolution. Our study reveals the first structure of a pLGIC at high resolution and provides an important model system for the investigation of the general mechanisms of ion permeation and gating within the family.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hilf, Ricarda J C -- Dutzler, Raimund -- England -- Nature. 2008 Mar 20;452(7185):375-9. doi: 10.1038/nature06717. Epub 2008 Mar 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Zurich, Winterthurer Strasse 190, CH-8057 Zurich, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18322461" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Crystallography, X-Ray ; *Ion Channel Gating ; Ion Channels/*chemistry/*metabolism ; Ligands ; Models, Molecular ; Pectobacterium chrysanthemi/*chemistry ; Protein Structure, Secondary ; Static Electricity
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  • 75
    Publikationsdatum: 2008-02-01
    Beschreibung: The transcription apparatus in Archaea can be described as a simplified version of its eukaryotic RNA polymerase (RNAP) II counterpart, comprising an RNAPII-like enzyme as well as two general transcription factors, the TATA-binding protein (TBP) and the eukaryotic TFIIB orthologue TFB. It has been widely understood that precise comparisons of cellular RNAP crystal structures could reveal structural elements common to all enzymes and that these insights would be useful in analysing components of each enzyme that enable it to perform domain-specific gene expression. However, the structure of archaeal RNAP has been limited to individual subunits. Here we report the first crystal structure of the archaeal RNAP from Sulfolobus solfataricus at 3.4 A resolution, completing the suite of multi-subunit RNAP structures from all three domains of life. We also report the high-resolution (at 1.76 A) crystal structure of the D/L subcomplex of archaeal RNAP and provide the first experimental evidence of any RNAP possessing an iron-sulphur (Fe-S) cluster, which may play a structural role in a key subunit of RNAP assembly. The striking structural similarity between archaeal RNAP and eukaryotic RNAPII highlights the simpler archaeal RNAP as an ideal model system for dissecting the molecular basis of eukaryotic transcription.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805805/" 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/PMC2805805/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hirata, Akira -- Klein, Brianna J -- Murakami, Katsuhiko S -- R01 GM071897/GM/NIGMS NIH HHS/ -- R01 GM071897-04/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Feb 14;451(7180):851-4. doi: 10.1038/nature06530. Epub 2008 Jan 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18235446" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Crystallography, X-Ray ; DNA-Directed RNA Polymerases/*chemistry/metabolism ; Iron-Sulfur Proteins/chemistry/metabolism ; Models, Molecular ; Protein Folding ; Protein Structure, Tertiary ; Protein Subunits/chemistry/metabolism ; Saccharomyces cerevisiae/enzymology ; Sulfolobus solfataricus/*enzymology ; Taq Polymerase/chemistry
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  • 76
    Publikationsdatum: 2008-03-07
    Beschreibung: The classical RNA secondary structure model considers A.U and G.C Watson-Crick as well as G.U wobble base pairs. Here we substitute it for a new one, in which sets of nucleotide cyclic motifs define RNA structures. This model allows us to unify all base pairing energetic contributions in an effective scoring function to tackle the problem of RNA folding. We show how pipelining two computer algorithms based on nucleotide cyclic motifs, MC-Fold and MC-Sym, reproduces a series of experimentally determined RNA three-dimensional structures from the sequence. This demonstrates how crucial the consideration of all base-pairing interactions is in filling the gap between sequence and structure. We use the pipeline to define rules of precursor microRNA folding in double helices, despite the presence of a number of presumed mismatches and bulges, and to propose a new model of the human immunodeficiency virus-1 -1 frame-shifting element.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Parisien, Marc -- Major, Francois -- England -- Nature. 2008 Mar 6;452(7183):51-5. doi: 10.1038/nature06684.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Research in Immunology and Cancer, Department of Computer Science and Operations Research, Universite de Montreal, PO Box 6128, Downtown Station, Montreal, Quebec H3C 3J7, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18322526" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Algorithms ; Base Pairing ; Base Sequence ; *Computational Biology ; Frameshifting, Ribosomal ; Genes, gag/genetics ; Genes, pol/genetics ; HIV-1/genetics ; Humans ; MicroRNAs/chemistry/metabolism ; Models, Genetic ; Models, Molecular ; Molecular Sequence Data ; *Nucleic Acid Conformation ; RNA/*chemistry/*genetics ; RNA Precursors/chemistry/metabolism ; RNA, Viral/chemistry/genetics/metabolism ; *Software ; Thermodynamics
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  • 77
    Publikationsdatum: 2008-06-20
    Beschreibung: In the G-protein-coupled receptor (GPCR) rhodopsin, the inactivating ligand 11-cis-retinal is bound in the seven-transmembrane helix (TM) bundle and is cis/trans isomerized by light to form active metarhodopsin II. With metarhodopsin II decay, all-trans-retinal is released, and opsin is reloaded with new 11-cis-retinal. Here we present the crystal structure of ligand-free native opsin from bovine retinal rod cells at 2.9 angstrom (A) resolution. Compared to rhodopsin, opsin shows prominent structural changes in the conserved E(D)RY and NPxxY(x)(5,6)F regions and in TM5-TM7. At the cytoplasmic side, TM6 is tilted outwards by 6-7 A, whereas the helix structure of TM5 is more elongated and close to TM6. These structural changes, some of which were attributed to an active GPCR state, reorganize the empty retinal-binding pocket to disclose two openings that may serve the entry and exit of retinal. The opsin structure sheds new light on ligand binding to GPCRs and on GPCR activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Park, Jung Hee -- Scheerer, Patrick -- Hofmann, Klaus Peter -- Choe, Hui-Woog -- Ernst, Oliver Peter -- England -- Nature. 2008 Jul 10;454(7201):183-7. doi: 10.1038/nature07063. Epub 2008 Jun 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Medizinische Physik und Biophysik (CC2), Charite-Universitatsmedizin Berlin, Chariteplatz 1, D-10117 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18563085" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding Sites ; Cattle ; Conserved Sequence ; Crystallography, X-Ray ; Ligands ; Models, Molecular ; Protein Conformation ; Protein Folding ; Receptors, G-Protein-Coupled/*chemistry/metabolism ; Retinal Rod Photoreceptor Cells/chemistry/cytology ; Retinaldehyde/chemistry/metabolism ; Rhodopsin/chemistry ; Rod Opsins/*chemistry/metabolism
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  • 78
    facet.materialart.
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    Nature Publishing Group (NPG)
    Publikationsdatum: 2008-09-27
    Beschreibung: 〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2668937/" 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/PMC2668937/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schwartz, Thue W -- Hubbell, Wayne L -- R01 EY005216/EY/NEI NIH HHS/ -- R01 EY005216-26/EY/NEI NIH HHS/ -- England -- Nature. 2008 Sep 25;455(7212):473-4. doi: 10.1038/455473a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18818642" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding Sites ; Cattle ; Crystallography, X-Ray ; GTP-Binding Protein alpha Subunits/*chemistry/*metabolism ; Models, Molecular ; Protein Conformation ; Rhodopsin/chemistry/metabolism ; Rod Opsins/*chemistry/*metabolism
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  • 79
    Publikationsdatum: 2008-02-22
    Beschreibung: The human APOBEC3G (apolipoprotein B messenger-RNA-editing enzyme, catalytic polypeptide-like 3G) protein is a single-strand DNA deaminase that inhibits the replication of human immunodeficiency virus-1 (HIV-1), other retroviruses and retrotransposons. APOBEC3G anti-viral activity is circumvented by most retroelements, such as through degradation by HIV-1 Vif. APOBEC3G is a member of a family of polynucleotide cytosine deaminases, several of which also target distinct physiological substrates. For instance, APOBEC1 edits APOB mRNA and AID deaminates antibody gene DNA. Although structures of other family members exist, none of these proteins has elicited polynucleotide cytosine deaminase or anti-viral activity. Here we report a solution structure of the human APOBEC3G catalytic domain. Five alpha-helices, including two that form the zinc-coordinating active site, are arranged over a hydrophobic platform consisting of five beta-strands. NMR DNA titration experiments, computational modelling, phylogenetic conservation and Escherichia coli-based activity assays combine to suggest a DNA-binding model in which a brim of positively charged residues positions the target cytosine for catalysis. The structure of the APOBEC3G catalytic domain will help us to understand functions of other family members and interactions that occur with pathogenic proteins such as HIV-1 Vif.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Kuan-Ming -- Harjes, Elena -- Gross, Phillip J -- Fahmy, Amr -- Lu, Yongjian -- Shindo, Keisuke -- Harris, Reuben S -- Matsuo, Hiroshi -- R21 AI073167/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Mar 6;452(7183):116-9. doi: 10.1038/nature06638. Epub 2008 Feb 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Molecular Biology and Biophysics, [of Minnesota, Minneapolis, Minnesota 55455, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18288108" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Catalysis ; *Catalytic Domain ; Cytidine Deaminase/*chemistry/genetics/*metabolism ; DNA, Single-Stranded/chemistry/metabolism ; DNA-Binding Proteins/chemistry/genetics/metabolism ; HIV-1/*physiology ; Humans ; Hydrophobic and Hydrophilic Interactions ; Models, Molecular ; *Nuclear Magnetic Resonance, Biomolecular ; Protein Structure, Secondary ; Zinc/metabolism
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  • 80
    Publikationsdatum: 2008-09-06
    Beschreibung: Epigenetic inheritance in mammals is characterized by high-fidelity replication of CpG methylation patterns during development. UHRF1 (also known as ICBP90 in humans and Np95 in mouse) is an E3 ligase important for the maintenance of global and local DNA methylation in vivo. The preferential affinity of UHRF1 for hemi-methylated DNA over symmetrically methylated DNA by means of its SET and RING-associated (SRA) domain and its association with the maintenance DNA methyltransferase 1 (DNMT1) suggests a role in replication of the epigenetic code. Here we report the 1.7 A crystal structure of the apo SRA domain of human UHRF1 and a 2.2 A structure of its complex with hemi-methylated DNA, revealing a previously unknown reading mechanism for methylated CpG sites (mCpG). The SRA-DNA complex has several notable structural features including a binding pocket that accommodates the 5-methylcytosine that is flipped out of the duplex DNA. Two specialized loops reach through the resulting gap in the DNA from both the major and the minor grooves to read the other three bases of the CpG duplex. The major groove loop confers both specificity for the CpG dinucleotide and discrimination against methylation of deoxycytidine of the complementary strand. The structure, along with mutagenesis data, suggests how UHRF1 acts as a key factor for DNMT1 maintenance methylation through recognition of a fundamental unit of epigenetic inheritance, mCpG.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Avvakumov, George V -- Walker, John R -- Xue, Sheng -- Li, Yanjun -- Duan, Shili -- Bronner, Christian -- Arrowsmith, Cheryl H -- Dhe-Paganon, Sirano -- Wellcome Trust/United Kingdom -- England -- Nature. 2008 Oct 9;455(7214):822-5. doi: 10.1038/nature07273. Epub 2008 Sep 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Genomics Consortium, University of Toronto, 100 College Street, Toronto, Ontario M5G 1L5, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18772889" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 5-Methylcytosine/metabolism ; Binding Sites ; CCAAT-Enhancer-Binding Proteins/*chemistry/*metabolism ; CpG Islands/genetics ; Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; DNA (Cytosine-5-)-Methyltransferase/metabolism ; *DNA Methylation ; Epigenesis, Genetic ; Humans ; Models, Molecular ; Molecular Conformation ; Protein Structure, Tertiary
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 81
    Publikationsdatum: 2008-01-04
    Beschreibung: The 'RNA world' hypothesis holds that during evolution the structural and enzymatic functions initially served by RNA were assumed by proteins, leading to the latter's domination of biological catalysis. This progression can still be seen in modern biology, where ribozymes, such as the ribosome and RNase P, have evolved into protein-dependent RNA catalysts ('RNPzymes'). Similarly, group I introns use RNA-catalysed splicing reactions, but many function as RNPzymes bound to proteins that stabilize their catalytically active RNA structure. One such protein, the Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (TyrRS; CYT-18), is bifunctional and both aminoacylates mitochondrial tRNA(Tyr) and promotes the splicing of mitochondrial group I introns. Here we determine a 4.5-A co-crystal structure of the Twort orf142-I2 group I intron ribozyme bound to splicing-active, carboxy-terminally truncated CYT-18. The structure shows that the group I intron binds across the two subunits of the homodimeric protein with a newly evolved RNA-binding surface distinct from that which binds tRNA(Tyr). This RNA binding surface provides an extended scaffold for the phosphodiester backbone of the conserved catalytic core of the intron RNA, allowing the protein to promote the splicing of a wide variety of group I introns. The group I intron-binding surface includes three small insertions and additional structural adaptations relative to non-splicing bacterial TyrRSs, indicating a multistep adaptation for splicing function. The co-crystal structure provides insight into how CYT-18 promotes group I intron splicing, how it evolved to have this function, and how proteins could have incrementally replaced RNA structures during the transition from an RNA world to an RNP world.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Paukstelis, Paul J -- Chen, Jui-Hui -- Chase, Elaine -- Lambowitz, Alan M -- Golden, Barbara L -- England -- Nature. 2008 Jan 3;451(7174):94-7. doi: 10.1038/nature06413.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Cellular and Molecular Biology, Department of Chemistry and Biochemistry, and Section of Molecular Genetics and Microbiology, School of Biological Sciences, 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/18172503" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Crystallography, X-Ray ; Introns/*genetics ; Models, Molecular ; Molecular Conformation ; Neurospora crassa/*enzymology ; Protein Binding ; RNA/genetics/metabolism ; *RNA Splicing ; RNA, Catalytic/chemistry/genetics/metabolism ; RNA-Binding Proteins/*chemistry/*metabolism ; Staphylococcus Phages/enzymology/genetics ; Tyrosine-tRNA Ligase/*chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 82
    Publikationsdatum: 2008-10-14
    Beschreibung: The APOBEC family members are involved in diverse biological functions. APOBEC3G restricts the replication of human immunodeficiency virus (HIV), hepatitis B virus and retroelements by cytidine deamination on single-stranded DNA or by RNA binding. Here we report the high-resolution crystal structure of the carboxy-terminal deaminase domain of APOBEC3G (APOBEC3G-CD2) purified from Escherichia coli. The APOBEC3G-CD2 structure has a five-stranded beta-sheet core that is common to all known deaminase structures and closely resembles the structure of another APOBEC protein, APOBEC2 (ref. 5). A comparison of APOBEC3G-CD2 with other deaminase structures shows a structural conservation of the active-site loops that are directly involved in substrate binding. In the X-ray structure, these APOBEC3G active-site loops form a continuous 'substrate groove' around the active centre. The orientation of this putative substrate groove differs markedly (by 90 degrees) from the groove predicted by the NMR structure. We have introduced mutations around the groove, and have identified residues involved in substrate specificity, single-stranded DNA binding and deaminase activity. These results provide a basis for understanding the underlying mechanisms of substrate specificity for the APOBEC family.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2714533/" 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/PMC2714533/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Holden, Lauren G -- Prochnow, Courtney -- Chang, Y Paul -- Bransteitter, Ronda -- Chelico, Linda -- Sen, Udayaditya -- Stevens, Raymond C -- Goodman, Myron F -- Chen, Xiaojiang S -- R01 AI055926/AI/NIAID NIH HHS/ -- R01 AI055926-05/AI/NIAID NIH HHS/ -- England -- Nature. 2008 Nov 6;456(7218):121-4. doi: 10.1038/nature07357. Epub 2008 Oct 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18849968" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antiviral Agents ; *Catalytic Domain ; Crystallography, X-Ray ; Cytidine Deaminase/*chemistry/genetics/isolation & purification/*metabolism ; DNA, Single-Stranded/metabolism ; Escherichia coli ; Humans ; Models, Molecular ; Muscle Proteins/chemistry ; Mutant Proteins/chemistry/genetics/metabolism ; Mutation ; Nuclear Magnetic Resonance, Biomolecular ; Protein Structure, Secondary ; Structural Homology, Protein ; Structure-Activity Relationship ; Substrate Specificity
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 83
    Publikationsdatum: 2008-05-24
    Beschreibung: The RecA family of ATPases mediates homologous recombination, a reaction essential for maintaining genomic integrity and for generating genetic diversity. RecA, ATP and single-stranded DNA (ssDNA) form a helical filament that binds to double-stranded DNA (dsDNA), searches for homology, and then catalyses the exchange of the complementary strand, producing a new heteroduplex. Here we have solved the crystal structures of the Escherichia coli RecA-ssDNA and RecA-heteroduplex filaments. They show that ssDNA and ATP bind to RecA-RecA interfaces cooperatively, explaining the ATP dependency of DNA binding. The ATP gamma-phosphate is sensed across the RecA-RecA interface by two lysine residues that also stimulate ATP hydrolysis, providing a mechanism for DNA release. The DNA is underwound and stretched globally, but locally it adopts a B-DNA-like conformation that restricts the homology search to Watson-Crick-type base pairing. The complementary strand interacts primarily through base pairing, making heteroduplex formation strictly dependent on complementarity. The underwound, stretched filament conformation probably evolved to destabilize the donor duplex, freeing the complementary strand for homology sampling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chen, Zhucheng -- Yang, Haijuan -- Pavletich, Nikola P -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 May 22;453(7194):489-4. doi: 10.1038/nature06971.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18497818" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/metabolism ; Binding Sites ; Crystallography, X-Ray ; DNA/*chemistry/genetics/*metabolism ; DNA, Single-Stranded/chemistry/genetics/metabolism ; Escherichia coli/*enzymology/genetics ; Models, Molecular ; Nucleic Acid Conformation ; Nucleic Acid Heteroduplexes/chemistry/genetics/metabolism ; Protein Conformation ; Rec A Recombinases/*chemistry/*metabolism ; *Recombination, Genetic/genetics ; *Sequence Homology, Nucleic Acid
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 84
    Publikationsdatum: 2008-07-25
    Beschreibung: During infection, enterohaemorrhagic Escherichia coli (EHEC) takes over the actin cytoskeleton of eukaryotic cells by injecting the EspF(U) protein into the host cytoplasm. EspF(U) controls actin by activating members of the Wiskott-Aldrich syndrome protein (WASP) family. Here we show that EspF(U) binds to the autoinhibitory GTPase binding domain (GBD) in WASP proteins and displaces it from the activity-bearing VCA domain (for verprolin homology, central hydrophobic and acidic regions). This interaction potently activates WASP and neural (N)-WASP in vitro and induces localized actin assembly in cells. In the solution structure of the GBD-EspF(U) complex, EspF(U) forms an amphipathic helix that binds the GBD, mimicking interactions of the VCA domain in autoinhibited WASP. Thus, EspF(U) activates WASP by competing directly for the VCA binding site on the GBD. This mechanism is distinct from that used by the eukaryotic activators Cdc42 and SH2 domains, which globally destabilize the GBD fold to release the VCA. Such diversity of mechanism in WASP proteins is distinct from other multimodular systems, and may result from the intrinsically unstructured nature of the isolated GBD and VCA elements. The structural incompatibility of the GBD complexes with EspF(U) and Cdc42/SH2, plus high-affinity EspF(U) binding, enable EHEC to hijack the eukaryotic cytoskeletal machinery effectively.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2719906/" 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/PMC2719906/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cheng, Hui-Chun -- Skehan, Brian M -- Campellone, Kenneth G -- Leong, John M -- Rosen, Michael K -- R01 AI046454/AI/NIAID NIH HHS/ -- R01 AI046454-09/AI/NIAID NIH HHS/ -- R01 GM056322/GM/NIGMS NIH HHS/ -- R01 GM056322-12A1/GM/NIGMS NIH HHS/ -- R01-AI46454/AI/NIAID NIH HHS/ -- R01-GM56322/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Aug 21;454(7207):1009-13. doi: 10.1038/nature07160. Epub 2008 Jul 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18650809" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Actins/metabolism ; Amino Acid Sequence ; Animals ; Carrier Proteins/chemistry/*metabolism ; Cells, Cultured ; Enterohemorrhagic Escherichia coli/chemistry/genetics/*metabolism ; Escherichia coli Proteins/chemistry/*metabolism ; Fibroblasts/cytology ; Mice ; Models, Molecular ; Molecular Sequence Data ; Protein Structure, Tertiary ; Wiskott-Aldrich Syndrome Protein/chemistry/*metabolism ; Wiskott-Aldrich Syndrome Protein, Neuronal/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 85
    Publikationsdatum: 2008-08-01
    Beschreibung: The envelope glycoproteins (Env) of human and simian immunodeficiency viruses (HIV and SIV, respectively) mediate virus binding to the cell surface receptor CD4 on target cells to initiate infection. Env is a heterodimer of a transmembrane glycoprotein (gp41) and a surface glycoprotein (gp120), and forms trimers on the surface of the viral membrane. Using cryo-electron tomography combined with three-dimensional image classification and averaging, we report the three-dimensional structures of trimeric Env displayed on native HIV-1 in the unliganded state, in complex with the broadly neutralizing antibody b12 and in a ternary complex with CD4 and the 17b antibody. By fitting the known crystal structures of the monomeric gp120 core in the b12- and CD4/17b-bound conformations into the density maps derived by electron tomography, we derive molecular models for the native HIV-1 gp120 trimer in unliganded and CD4-bound states. We demonstrate that CD4 binding results in a major reorganization of the Env trimer, causing an outward rotation and displacement of each gp120 monomer. This appears to be coupled with a rearrangement of the gp41 region along the central axis of the trimer, leading to closer contact between the viral and target cell membranes. Our findings elucidate the structure and conformational changes of trimeric HIV-1 gp120 relevant to antibody neutralization and attachment to target cells.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2610422/" 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/PMC2610422/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liu, Jun -- Bartesaghi, Alberto -- Borgnia, Mario J -- Sapiro, Guillermo -- Subramaniam, Sriram -- Z01 BC010825-01/Intramural NIH HHS/ -- England -- Nature. 2008 Sep 4;455(7209):109-13. doi: 10.1038/nature07159. Epub 2008 Jul 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18668044" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antigens, CD4/chemistry/metabolism ; Cryoelectron Microscopy ; HIV Envelope Protein gp120/*chemistry/immunology/*metabolism ; HIV-1/*chemistry ; Immunoglobulin Fab Fragments/chemistry/immunology ; Models, Molecular ; Protein Binding ; Protein Structure, Quaternary ; Protein Subunits/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 86
    Publikationsdatum: 2008-09-12
    Beschreibung: In bacteria, the intracellular concentration of several amino acids is controlled by riboswitches. One of the important regulatory circuits involves lysine-specific riboswitches, which direct the biosynthesis and transport of lysine and precursors common for lysine and other amino acids. To understand the molecular basis of amino acid recognition by riboswitches, here we present the crystal structure of the 174-nucleotide sensing domain of the Thermotoga maritima lysine riboswitch in the lysine-bound (1.9 angstrom (A)) and free (3.1 A) states. The riboswitch features an unusual and intricate architecture, involving three-helical and two-helical bundles connected by a compact five-helical junction and stabilized by various long-range tertiary interactions. Lysine interacts with the junctional core of the riboswitch and is specifically recognized through shape-complementarity within the elongated binding pocket and through several direct and K(+)-mediated hydrogen bonds to its charged ends. Our structural and biochemical studies indicate preformation of the riboswitch scaffold and identify conformational changes associated with the formation of a stable lysine-bound state, which prevents alternative folding of the riboswitch and facilitates formation of downstream regulatory elements. We have also determined several structures of the riboswitch bound to different lysine analogues, including antibiotics, in an effort to understand the ligand-binding capabilities of the lysine riboswitch and understand the nature of antibiotic resistance. Our results provide insights into a mechanism of lysine-riboswitch-dependent gene control at the molecular level, thereby contributing to continuing efforts at exploration of the pharmaceutical and biotechnological potential of riboswitches.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3726722/" 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/PMC3726722/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Serganov, Alexander -- Huang, Lili -- Patel, Dinshaw J -- R01 GM073618/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Oct 30;455(7217):1263-7. doi: 10.1038/nature07326. Epub 2008 Sep 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA. serganoa@mskcc.org〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18784651" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Crystallography, X-Ray ; *Gene Expression Regulation, Bacterial ; Lysine/chemistry/*genetics/*metabolism ; Models, Molecular ; *Nucleic Acid Conformation ; RNA, Bacterial/*chemistry/genetics/*metabolism ; Thermotoga maritima/chemistry/*genetics
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  • 87
    Publikationsdatum: 2008-02-15
    Beschreibung: The transcriptional coactivator p300/CBP (CREBBP) is a histone acetyltransferase (HAT) that regulates gene expression by acetylating histones and other transcription factors. Dysregulation of p300/CBP HAT activity contributes to various diseases including cancer. Sequence alignments, enzymology experiments and inhibitor studies on p300/CBP have led to contradictory results about its catalytic mechanism and its structural relation to the Gcn5/PCAF and MYST HATs. Here we describe a high-resolution X-ray crystal structure of a semi-synthetic heterodimeric p300 HAT domain in complex with a bi-substrate inhibitor, Lys-CoA. This structure shows that p300/CBP is a distant cousin of other structurally characterized HATs, but reveals several novel features that explain the broad substrate specificity and preference for nearby basic residues. Based on this structure and accompanying biochemical data, we propose that p300/CBP uses an unusual 'hit-and-run' (Theorell-Chance) catalytic mechanism that is distinct from other characterized HATs. Several disease-associated mutations can also be readily accounted for by the p300 HAT structure. These studies pave the way for new epigenetic therapies involving modulation of p300/CBP HAT activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liu, Xin -- Wang, Ling -- Zhao, Kehao -- Thompson, Paul R -- Hwang, Yousang -- Marmorstein, Ronen -- Cole, Philip A -- England -- Nature. 2008 Feb 14;451(7180):846-50. doi: 10.1038/nature06546.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Program in Gene Expression and Regulation, The Wistar Institute, 3601 Spruce Street, Philadelphia, Pennsylvania 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18273021" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acetylation ; Amino Acid Sequence ; Catalysis ; Crystallography, X-Ray ; Dimerization ; Histone Acetyltransferases/antagonists & inhibitors/chemical ; synthesis/*chemistry/*metabolism ; Kinetics ; Models, Molecular ; Molecular Sequence Data ; Protein Structure, Tertiary ; Structure-Activity Relationship ; p300-CBP Transcription Factors/antagonists & inhibitors/chemical ; synthesis/*chemistry/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 88
    Publikationsdatum: 2008-08-16
    Beschreibung: Non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) produce numerous secondary metabolites with various therapeutic/antibiotic properties. Like fatty acid synthases (FAS), these enzymes are organized in modular assembly lines in which each module, made of conserved domains, incorporates a given monomer unit into the growing chain. Knowledge about domain or module interactions may enable reengineering of this assembly line enzymatic organization and open avenues for the design of new bioactive compounds with improved therapeutic properties. So far, little structural information has been available on how the domains interact and communicate. This may be because of inherent interdomain mobility hindering crystallization, or because crystallized molecules may not represent the active domain orientations. In solution, the large size and internal dynamics of multidomain fragments (〉35 kilodaltons) make structure determination by nuclear magnetic resonance a challenge and require advanced technologies. Here we present the solution structure of the apo-thiolation-thioesterase (T-TE) di-domain fragment of the Escherichia coli enterobactin synthetase EntF NRPS subunit. In the holoenzyme, the T domain carries the growing chain tethered to a 4'-phosphopantetheine whereas the TE domain catalyses hydrolysis and cyclization of the iron chelator enterobactin. The T-TE di-domain forms a compact but dynamic structure with a well-defined domain interface; the two active sites are at a suitable distance for substrate transfer from T to TE. We observe extensive interdomain and intradomain motions for well-defined regions and show that these are modulated by interactions with proteins that participate in the biosynthesis. The T-TE interaction described here provides a model for NRPS, PKS and FAS function in general as T-TE-like di-domains typically catalyse the last step in numerous assembly-line chain-termination machineries.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597408/" 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/PMC2597408/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frueh, Dominique P -- Arthanari, Haribabu -- Koglin, Alexander -- Vosburg, David A -- Bennett, Andrew E -- Walsh, Christopher T -- Wagner, Gerhard -- EB 002026/EB/NIBIB NIH HHS/ -- GM066360/GM/NIGMS NIH HHS/ -- GM47467/GM/NIGMS NIH HHS/ -- P01 GM047467/GM/NIGMS NIH HHS/ -- P01 GM047467-11/GM/NIGMS NIH HHS/ -- P01 GM047467-110009/GM/NIGMS NIH HHS/ -- P01 GM047467-12/GM/NIGMS NIH HHS/ -- P01 GM047467-13/GM/NIGMS NIH HHS/ -- P01 GM047467-14/GM/NIGMS NIH HHS/ -- P01 GM047467-15/GM/NIGMS NIH HHS/ -- P01 GM047467-16/GM/NIGMS NIH HHS/ -- P01 GM047467-160012/GM/NIGMS NIH HHS/ -- P01 GM047467-17/GM/NIGMS NIH HHS/ -- P01 GM047467-170012/GM/NIGMS NIH HHS/ -- P41 EB002026/EB/NIBIB NIH HHS/ -- P41 EB002026-28/EB/NIBIB NIH HHS/ -- P41 EB002026-29/EB/NIBIB NIH HHS/ -- P41 EB002026-30/EB/NIBIB NIH HHS/ -- P41 EB002026-31/EB/NIBIB NIH HHS/ -- P41 EB002026-32/EB/NIBIB NIH HHS/ -- P41 EB002026-33/EB/NIBIB NIH HHS/ -- P41 GM066360/GM/NIGMS NIH HHS/ -- P41 GM066360-01/GM/NIGMS NIH HHS/ -- P41 GM066360-02/GM/NIGMS NIH HHS/ -- P41 GM066360-03/GM/NIGMS NIH HHS/ -- P41 GM066360-04/GM/NIGMS NIH HHS/ -- P41 GM066360-05/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Aug 14;454(7206):903-6. doi: 10.1038/nature07162.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA. dominique_frueh@hms.harvard.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18704088" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; Catalysis ; Enterobactin/biosynthesis ; Escherichia coli/*enzymology/genetics ; Ligases/*chemistry/genetics/*metabolism ; Models, Molecular ; Multienzyme Complexes/*chemistry/genetics/*metabolism ; Nuclear Magnetic Resonance, Biomolecular ; *Peptide Biosynthesis, Nucleic Acid-Independent ; Protein Structure, Tertiary ; Protein Subunits/chemistry/genetics/metabolism
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    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
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  • 89
    Publikationsdatum: 2009-11-26
    Beschreibung: Mutations in the enzyme cytosolic isocitrate dehydrogenase 1 (IDH1) are a common feature of a major subset of primary human brain cancers. These mutations occur at a single amino acid residue of the IDH1 active site, resulting in loss of the enzyme's ability to catalyse conversion of isocitrate to alpha-ketoglutarate. However, only a single copy of the gene is mutated in tumours, raising the possibility that the mutations do not result in a simple loss of function. Here we show that cancer-associated IDH1 mutations result in a new ability of the enzyme to catalyse the NADPH-dependent reduction of alpha-ketoglutarate to R(-)-2-hydroxyglutarate (2HG). Structural studies demonstrate that when arginine 132 is mutated to histidine, residues in the active site are shifted to produce structural changes consistent with reduced oxidative decarboxylation of isocitrate and acquisition of the ability to convert alpha-ketoglutarate to 2HG. Excess accumulation of 2HG has been shown to lead to an elevated risk of malignant brain tumours in patients with inborn errors of 2HG metabolism. Similarly, in human malignant gliomas harbouring IDH1 mutations, we find markedly elevated levels of 2HG. These data demonstrate that the IDH1 mutations result in production of the onco-metabolite 2HG, and indicate that the excess 2HG which accumulates in vivo contributes to the formation and malignant progression of gliomas.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818760/" 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/PMC2818760/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dang, Lenny -- White, David W -- Gross, Stefan -- Bennett, Bryson D -- Bittinger, Mark A -- Driggers, Edward M -- Fantin, Valeria R -- Jang, Hyun Gyung -- Jin, Shengfang -- Keenan, Marie C -- Marks, Kevin M -- Prins, Robert M -- Ward, Patrick S -- Yen, Katharine E -- Liau, Linda M -- Rabinowitz, Joshua D -- Cantley, Lewis C -- Thompson, Craig B -- Vander Heiden, Matthew G -- Su, Shinsan M -- P01 CA104838/CA/NCI NIH HHS/ -- P01 CA104838-05/CA/NCI NIH HHS/ -- P30 EB009998/EB/NIBIB NIH HHS/ -- R01 CA105463/CA/NCI NIH HHS/ -- R01 CA105463-06/CA/NCI NIH HHS/ -- R21 CA128620/CA/NCI NIH HHS/ -- England -- Nature. 2009 Dec 10;462(7274):739-44. doi: 10.1038/nature08617. Epub .〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Agios Pharmaceuticals, Cambridge, Massachusetts 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19935646" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Arginine/genetics ; Brain Neoplasms/*genetics/*metabolism/pathology ; Catalytic Domain ; Cell Line ; Crystallography, X-Ray ; Disease Progression ; Enzyme Assays ; Glioma/genetics/metabolism/pathology ; Glutarates/*metabolism ; Histidine/genetics/metabolism ; Humans ; Isocitrate Dehydrogenase/*genetics/*metabolism ; Ketoglutaric Acids/metabolism ; Models, Molecular ; Mutant Proteins/*genetics/*metabolism ; Mutation/genetics ; Protein Conformation
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    Publikationsdatum: 2009-03-06
    Beschreibung: Osmoregulated transporters sense intracellular osmotic pressure and respond to hyperosmotic stress by accumulation of osmolytes to restore normal hydration levels. Here we report the determination of the X-ray structure of a member of the family of betaine/choline/carnitine transporters, the Na(+)-coupled symporter BetP from Corynebacterium glutamicum, which is a highly effective osmoregulated uptake system for glycine betaine. Glycine betaine is bound in a tryptophan box occluded from both sides of the membrane with aromatic side chains lining the transport pathway. BetP has the same overall fold as three unrelated Na(+)-coupled symporters. Whereas these are crystallized in either the outward-facing or the inward-facing conformation, the BetP structure reveals a unique intermediate conformation in the Na(+)-coupled transport cycle. The trimeric architecture of BetP and the break in three-fold symmetry by the osmosensing C-terminal helices suggest a regulatory mechanism of Na(+)-coupled osmolyte transport to counteract osmotic stress.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ressl, Susanne -- Terwisscha van Scheltinga, Anke C -- Vonrhein, Clemens -- Ott, Vera -- Ziegler, Christine -- England -- Nature. 2009 Mar 5;458(7234):47-52. doi: 10.1038/nature07819.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Planck Institute of Biophysics, Department of Structural Biology, 60438 Frankfurt am Main, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19262666" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Bacterial Proteins/*chemistry/genetics/*metabolism ; Betaine/*metabolism ; Binding Sites ; Carrier Proteins/*chemistry/genetics/*metabolism ; Corynebacterium glutamicum/*chemistry/genetics ; Crystallography, X-Ray ; Ion Transport ; Models, Molecular ; Protein Binding ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Sodium/*metabolism ; Structure-Activity Relationship
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    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    Publikationsdatum: 2009-11-27
    Beschreibung: Protein design provides a rigorous test of our knowledge about proteins and allows the creation of novel enzymes for biotechnological applications. Whereas progress has been made in designing proteins that mimic native proteins structurally, it is more difficult to design functional proteins. In comparison to recent successes in designing non-metalloproteins, it is even more challenging to rationally design metalloproteins that reproduce both the structure and function of native metalloenzymes. This is because protein metal-binding sites are much more varied than non-metal-containing sites, in terms of different metal ion oxidation states, preferred geometry and metal ion ligand donor sets. Because of their variability, it has been difficult to predict metal-binding site properties in silico, as many of the parameters, such as force fields, are ill-defined. Therefore, the successful design of a structural and functional metalloprotein would greatly advance the field of protein design and our understanding of enzymes. Here we report a successful, rational design of a structural and functional model of a metalloprotein, nitric oxide reductase (NOR), by introducing three histidines and one glutamate, predicted as ligands in the active site of NOR, into the distal pocket of myoglobin. A crystal structure of the designed protein confirms that the minimized computer model contains a haem/non-haem Fe(B) centre that is remarkably similar to that in the crystal structure. This designed protein also exhibits NO reduction activity, and so models both the structure and function of NOR, offering insight that the active site glutamate is required for both iron binding and activity. These results show that structural and functional metalloproteins can be rationally designed in silico.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4297211/" 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/PMC4297211/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yeung, Natasha -- Lin, Ying-Wu -- Gao, Yi-Gui -- Zhao, Xuan -- Russell, Brandy S -- Lei, Lanyu -- Miner, Kyle D -- Robinson, Howard -- Lu, Yi -- GM062211/GM/NIGMS NIH HHS/ -- R01 GM062211/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Dec 24;462(7276):1079-82. doi: 10.1038/nature08620. Epub 2009 Nov 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19940850" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Crystallization ; Iron/metabolism ; Models, Molecular ; Myoglobin/chemistry ; Nitric Oxide/metabolism ; Oxidoreductases/*chemical synthesis/*chemistry/metabolism ; Protein Binding ; Protein Structure, Tertiary
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Publikationsdatum: 2009-11-20
    Beschreibung: Glutamate transporters are integral membrane proteins that catalyse a thermodynamically uphill uptake of the neurotransmitter glutamate from the synaptic cleft into the cytoplasm of glia and neuronal cells by harnessing the energy of pre-existing electrochemical gradients of ions. Crucial to the reaction is the conformational transition of the transporters between outward and inward facing states, in which the substrate binding sites are accessible from the extracellular space and the cytoplasm, respectively. Here we describe the crystal structure of a double cysteine mutant of a glutamate transporter homologue from Pyrococcus horikoshii, Glt(Ph), which is trapped in the inward facing state by cysteine crosslinking. Together with the previously determined crystal structures of Glt(Ph) in the outward facing state, the structure of the crosslinked mutant allows us to propose a molecular mechanism by which Glt(Ph) and, by analogy, mammalian glutamate transporters mediate sodium-coupled substrate uptake.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2934767/" 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/PMC2934767/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Reyes, Nicolas -- Ginter, Christopher -- Boudker, Olga -- R01 NS064357/NS/NINDS NIH HHS/ -- R01 NS064357-01A1/NS/NINDS NIH HHS/ -- England -- Nature. 2009 Dec 17;462(7275):880-5. doi: 10.1038/nature08616. Epub 2009 Nov 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Biophysics, Weill Cornell Medical College, 1300 York Avenue, Box 75, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19924125" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Transport System X-AG/*chemistry/genetics/*metabolism ; Binding Sites ; Biological Transport ; Cross-Linking Reagents ; Crystallography, X-Ray ; Cysteine/genetics/metabolism ; Models, Molecular ; Movement ; Mutant Proteins/chemistry/genetics/metabolism ; Protein Structure, Tertiary ; Pyrococcus horikoshii/*chemistry ; Sodium/metabolism ; Structure-Activity Relationship
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Publikationsdatum: 2009-02-06
    Beschreibung: The heterotrimeric influenza virus polymerase, containing the PA, PB1 and PB2 proteins, catalyses viral RNA replication and transcription in the nucleus of infected cells. PB1 holds the polymerase active site and reportedly harbours endonuclease activity, whereas PB2 is responsible for cap binding. The PA amino terminus is understood to be the major functional part of the PA protein and has been implicated in several roles, including endonuclease and protease activities as well as viral RNA/complementary RNA promoter binding. Here we report the 2.2 angstrom (A) crystal structure of the N-terminal 197 residues of PA, termed PA(N), from an avian influenza H5N1 virus. The PA(N) structure has an alpha/beta architecture and reveals a bound magnesium ion coordinated by a motif similar to the (P)DX(N)(D/E)XK motif characteristic of many endonucleases. Structural comparisons and mutagenesis analysis of the motif identified in PA(N) provide further evidence that PA(N) holds an endonuclease active site. Furthermore, functional analysis with in vivo ribonucleoprotein reconstitution and direct in vitro endonuclease assays strongly suggest that PA(N) holds the endonuclease active site and has critical roles in endonuclease activity of the influenza virus polymerase, rather than PB1. The high conservation of this endonuclease active site among influenza strains indicates that PA(N) is an important target for the design of new anti-influenza therapeutics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yuan, Puwei -- Bartlam, Mark -- Lou, Zhiyong -- Chen, Shoudeng -- Zhou, Jie -- He, Xiaojing -- Lv, Zongyang -- Ge, Ruowen -- Li, Xuemei -- Deng, Tao -- Fodor, Ervin -- Rao, Zihe -- Liu, Yingfang -- G0700848/Medical Research Council/United Kingdom -- England -- Nature. 2009 Apr 16;458(7240):909-13. doi: 10.1038/nature07720. Epub 2009 Feb 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19194458" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Birds/virology ; Catalytic Domain ; Crystallography, X-Ray ; Endonucleases/*chemistry/genetics/*metabolism ; Influenza A Virus, H5N1 Subtype/*enzymology ; Influenza in Birds/*virology ; Models, Molecular ; Protein Subunits/chemistry/genetics/metabolism ; RNA Replicase/*chemistry/genetics/*metabolism ; Viral Proteins/*chemistry/genetics/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Publikationsdatum: 2009-05-05
    Beschreibung: The proteasome is a protease that controls diverse processes in eukaryotic cells. Its regulatory particle (RP) initiates the degradation of ubiquitin-protein conjugates by unfolding the substrate and translocating it into the proteasome core particle (CP) to be degraded. The RP has 19 subunits, and their pathway of assembly is not understood. Here we show that in the yeast Saccharomyces cerevisiae three proteins are found associated with RP but not with the RP-CP holoenzyme: Nas6, Rpn14 and Hsm3. Mutations in the corresponding genes confer proteasome loss-of-function phenotypes, despite their virtual absence from the holoenzyme. These effects result from deficient RP assembly. Thus, Nas6, Rpn14 and Hsm3 are RP chaperones. The RP contains six ATPases-the Rpt proteins-and each RP chaperone binds to the carboxy-terminal domain of a specific Rpt. We show in an accompanying study that RP assembly is templated through the Rpt C termini, apparently by their insertion into binding pockets in the CP. Thus, RP chaperones may regulate proteasome assembly by directly restricting the accessibility of Rpt C termini to the CP. In addition, competition between the RP chaperones and the CP for Rpt engagement may explain the release of RP chaperones as proteasomes mature.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727592/" 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/PMC2727592/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Roelofs, Jeroen -- Park, Soyeon -- Haas, Wilhelm -- Tian, Geng -- McAllister, Fiona E -- Huo, Ying -- Lee, Byung-Hoon -- Zhang, Fan -- Shi, Yigong -- Gygi, Steven P -- Finley, Daniel -- 5F32GM75737-2/GM/NIGMS NIH HHS/ -- GM043601/GM/NIGMS NIH HHS/ -- GM67945/GM/NIGMS NIH HHS/ -- R37 GM043601/GM/NIGMS NIH HHS/ -- R37 GM043601-19/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Jun 11;459(7248):861-5. doi: 10.1038/nature08063.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19412159" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/chemistry/metabolism ; Carrier Proteins/genetics/metabolism ; Conserved Sequence ; Evolution, Molecular ; Holoenzymes/chemistry/metabolism ; Humans ; Models, Molecular ; Molecular Chaperones/genetics/*metabolism ; Mutation ; Phenotype ; Proteasome Endopeptidase Complex/*chemistry/genetics/*metabolism ; Protein Binding ; Protein Structure, Tertiary ; Proto-Oncogene Proteins/genetics/metabolism ; Saccharomyces cerevisiae/*enzymology/genetics ; Saccharomyces cerevisiae Proteins/genetics/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Publikationsdatum: 2009-11-13
    Beschreibung: Direct inhibition of transcription factor complexes remains a central challenge in the discipline of ligand discovery. In general, these proteins lack surface involutions suitable for high-affinity binding by small molecules. Here we report the design of synthetic, cell-permeable, stabilized alpha-helical peptides that target a critical protein-protein interface in the NOTCH transactivation complex. We demonstrate that direct, high-affinity binding of the hydrocarbon-stapled peptide SAHM1 prevents assembly of the active transcriptional complex. Inappropriate NOTCH activation is directly implicated in the pathogenesis of several disease states, including T-cell acute lymphoblastic leukaemia (T-ALL). The treatment of leukaemic cells with SAHM1 results in genome-wide suppression of NOTCH-activated genes. Direct antagonism of the NOTCH transcriptional program causes potent, NOTCH-specific anti-proliferative effects in cultured cells and in a mouse model of NOTCH1-driven T-ALL.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951323/" 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/PMC2951323/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Moellering, Raymond E -- Cornejo, Melanie -- Davis, Tina N -- Del Bianco, Cristina -- Aster, Jon C -- Blacklow, Stephen C -- Kung, Andrew L -- Gilliland, D Gary -- Verdine, Gregory L -- Bradner, James E -- 5T32GM007598/GM/NIGMS NIH HHS/ -- N01-CO-12400/CO/NCI NIH HHS/ -- P01 CA119070/CA/NCI NIH HHS/ -- P01 CA119070-049001/CA/NCI NIH HHS/ -- R01 CA092433/CA/NCI NIH HHS/ -- R01 CA092433-06A2/CA/NCI NIH HHS/ -- R56 CA092433/CA/NCI NIH HHS/ -- R56 CA092433-06A1/CA/NCI NIH HHS/ -- T32 GM007598/GM/NIGMS NIH HHS/ -- T32 GM007598-30/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Nov 12;462(7270):182-8. doi: 10.1038/nature08543.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19907488" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Binding, Competitive ; Cell Line, Tumor ; Cell Membrane Permeability ; Cell Proliferation/drug effects ; DNA-Binding Proteins/chemistry/metabolism ; Disease Models, Animal ; Drosophila Proteins/chemistry ; Gene Expression Regulation, Neoplastic/drug effects ; Genome/drug effects/genetics ; Humans ; Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism ; Mice ; Models, Molecular ; Nuclear Proteins/chemistry ; Peptides/chemical synthesis/chemistry/metabolism/*pharmacology ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy/genetics/pathology ; Protein Binding/drug effects ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Receptor, Notch1/*antagonists & inhibitors/chemistry/metabolism ; Signal Transduction/drug effects ; Substrate Specificity ; Transcription Factors/chemistry/metabolism ; Transcriptional Activation/*drug effects
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Publikationsdatum: 2009-10-30
    Beschreibung: Enzymes use substrate-binding energy both to promote ground-state association and to stabilize the reaction transition state selectively. The monomeric homing endonuclease I-AniI cleaves with high sequence specificity in the centre of a 20-base-pair (bp) DNA target site, with the amino (N)-terminal domain of the enzyme making extensive binding interactions with the left (-) side of the target site and the similarly structured carboxy (C)-terminal domain interacting with the right (+) side. Here we show that, despite the approximate twofold symmetry of the enzyme-DNA complex, there is almost complete segregation of interactions responsible for substrate binding to the (-) side of the interface and interactions responsible for transition-state stabilization to the (+) side. Although single base-pair substitutions throughout the entire DNA target site reduce catalytic efficiency, mutations in the (-) DNA half-site almost exclusively increase the dissociation constant (K(D)) and the Michaelis constant under single-turnover conditions (K(M)*), and those in the (+) half-site primarily decrease the turnover number (k(cat)*). The reduction of activity produced by mutations on the (-) side, but not mutations on the (+) side, can be suppressed by tethering the substrate to the endonuclease displayed on the surface of yeast. This dramatic asymmetry in the use of enzyme-substrate binding energy for catalysis has direct relevance to the redesign of endonucleases to cleave genomic target sites for gene therapy and other applications. Computationally redesigned enzymes that achieve new specificities on the (-) side do so by modulating K(M)*, whereas redesigns with altered specificities on the (+) side modulate k(cat)*. Our results illustrate how classical enzymology and modern protein design can each inform the other.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2771326/" 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/PMC2771326/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thyme, Summer B -- Jarjour, Jordan -- Takeuchi, Ryo -- Havranek, James J -- Ashworth, Justin -- Scharenberg, Andrew M -- Stoddard, Barry L -- Baker, David -- GM084433/GM/NIGMS NIH HHS/ -- R00 RR024107/RR/NCRR NIH HHS/ -- R00 RR024107-03/RR/NCRR NIH HHS/ -- R00 RR024107-04/RR/NCRR NIH HHS/ -- RL1 GM084433/GM/NIGMS NIH HHS/ -- RL1 GM084433-03/GM/NIGMS NIH HHS/ -- RL1CA133832/CA/NCI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2009 Oct 29;461(7268):1300-4. doi: 10.1038/nature08508.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA. sthyme@u.washington.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19865174" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; *Biocatalysis ; Computational Biology ; *Computer Simulation ; DNA/chemistry/metabolism ; Endonucleases/chemistry/*metabolism ; Kinetics ; Models, Molecular ; Protein Binding ; Protein Conformation ; RNA-Directed DNA Polymerase/chemistry/*metabolism ; Saccharomyces cerevisiae/metabolism ; Substrate Specificity ; *Thermodynamics
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    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Publikationsdatum: 2009-12-17
    Beschreibung: Mistranslation arising from confusion of serine for alanine by alanyl-tRNA synthetases (AlaRSs) has profound functional consequences. Throughout evolution, two editing checkpoints prevent disease-causing mistranslation from confusing glycine or serine for alanine at the active site of AlaRS. In both bacteria and mice, Ser poses a bigger challenge than Gly. One checkpoint is the AlaRS editing centre, and the other is from widely distributed AlaXps-free-standing, genome-encoded editing proteins that clear Ser-tRNA(Ala). The paradox of misincorporating both a smaller (glycine) and a larger (serine) amino acid suggests a deep conflict for nature-designed AlaRS. Here we show the chemical basis for this conflict. Nine crystal structures, together with kinetic and mutational analysis, provided snapshots of adenylate formation for each amino acid. An inherent dilemma is posed by constraints of a structural design that pins down the alpha-amino group of the bound amino acid by using an acidic residue. This design, dating back more than 3 billion years, creates a serendipitous interaction with the serine OH that is difficult to avoid. Apparently because no better architecture for the recognition of alanine could be found, the serine misactivation problem was solved through free-standing AlaXps, which appeared contemporaneously with early AlaRSs. The results reveal unconventional problems and solutions arising from the historical design of the protein synthesis machinery.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2799227/" 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/PMC2799227/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guo, Min -- Chong, Yeeting E -- Shapiro, Ryan -- Beebe, Kirk -- Yang, Xiang-Lei -- Schimmel, Paul -- GM 15539/GM/NIGMS NIH HHS/ -- R01 GM015539/GM/NIGMS NIH HHS/ -- R01 GM015539-43/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Dec 10;462(7274):808-12. doi: 10.1038/nature08612.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Skaggs Institute for Chemical Biology and Department of Molecular Biology, The Scripps Research Institute, BCC-379, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20010690" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Alanine/*metabolism ; Alanine-tRNA Ligase/chemistry/genetics/*metabolism ; Aspartic Acid/genetics/metabolism ; Catalytic Domain ; Crystallization ; Escherichia coli/*enzymology ; Kinetics ; Models, Molecular ; Mutation ; *Protein Biosynthesis ; Protein Conformation ; RNA, Transfer, Ala/metabolism ; Serine/*metabolism ; Structure-Activity Relationship
    Print ISSN: 0028-0836
    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Publikationsdatum: 2009-04-17
    Beschreibung: Biosynthesis of the DNA base thymine depends on activity of the enzyme thymidylate synthase to catalyse the methylation of the uracil moiety of 2'-deoxyuridine-5'-monophosphate. All known thymidylate synthases rely on an active site residue of the enzyme to activate 2'-deoxyuridine-5'-monophosphate. This functionality has been demonstrated for classical thymidylate synthases, including human thymidylate synthase, and is instrumental in mechanism-based inhibition of these enzymes. Here we report an example of thymidylate biosynthesis that occurs without an enzymatic nucleophile. This unusual biosynthetic pathway occurs in organisms containing the thyX gene, which codes for a flavin-dependent thymidylate synthase (FDTS), and is present in several human pathogens. Our findings indicate that the putative active site nucleophile is not required for FDTS catalysis, and no alternative nucleophilic residues capable of serving this function can be identified. Instead, our findings suggest that a hydride equivalent (that is, a proton and two electrons) is transferred from the reduced flavin cofactor directly to the uracil ring, followed by an isomerization of the intermediate to form the product, 2'-deoxythymidine-5'-monophosphate. These observations indicate a very different chemical cascade than that of classical thymidylate synthases or any other known biological methylation. The findings and chemical mechanism proposed here, together with available structural data, suggest that selective inhibition of FDTSs, with little effect on human thymine biosynthesis, should be feasible. Because several human pathogens depend on FDTS for DNA biosynthesis, its unique mechanism makes it an attractive target for antibiotic drugs.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759699/" 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/PMC2759699/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Koehn, Eric M -- Fleischmann, Todd -- Conrad, John A -- Palfey, Bruce A -- Lesley, Scott A -- Mathews, Irimpan I -- Kohen, Amnon -- GM08270/GM/NIGMS NIH HHS/ -- R01 GM065368/GM/NIGMS NIH HHS/ -- R01 GM065368-05/GM/NIGMS NIH HHS/ -- R01 GM61087/GM/NIGMS NIH HHS/ -- U54GM074898/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Apr 16;458(7240):919-23. doi: 10.1038/nature07973.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19370033" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; Deoxyuracil Nucleotides/chemistry/metabolism ; Deuterium/metabolism ; Electrons ; Flavin-Adenine Dinucleotide/chemistry/metabolism ; Flavins/chemistry/*metabolism ; Helicobacter pylori/enzymology ; Humans ; Magnetic Resonance Spectroscopy ; Methylation ; Models, Molecular ; Mycobacterium tuberculosis/enzymology ; Protons ; Thermotoga maritima/*enzymology/*metabolism ; Thymidine/analogs & derivatives/metabolism ; Thymidine Monophosphate/*biosynthesis ; Thymidylate Synthase/antagonists & inhibitors/*genetics/*metabolism ; Uracil/metabolism
    Print ISSN: 0028-0836
    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Publikationsdatum: 2009-02-06
    Beschreibung: The influenza virus polymerase, a heterotrimer composed of three subunits, PA, PB1 and PB2, is responsible for replication and transcription of the eight separate segments of the viral RNA genome in the nuclei of infected cells. The polymerase synthesizes viral messenger RNAs using short capped primers derived from cellular transcripts by a unique 'cap-snatching' mechanism. The PB2 subunit binds the 5' cap of host pre-mRNAs, which are subsequently cleaved after 10-13 nucleotides by the viral endonuclease, hitherto thought to reside in the PB2 (ref. 5) or PB1 (ref. 2) subunits. Here we describe biochemical and structural studies showing that the amino-terminal 209 residues of the PA subunit contain the endonuclease active site. We show that this domain has intrinsic RNA and DNA endonuclease activity that is strongly activated by manganese ions, matching observations reported for the endonuclease activity of the intact trimeric polymerase. Furthermore, this activity is inhibited by 2,4-dioxo-4-phenylbutanoic acid, a known inhibitor of the influenza endonuclease. The crystal structure of the domain reveals a structural core closely resembling resolvases and type II restriction endonucleases. The active site comprises a histidine and a cluster of three acidic residues, conserved in all influenza viruses, which bind two manganese ions in a configuration similar to other two-metal-dependent endonucleases. Two active site residues have previously been shown to specifically eliminate the polymerase endonuclease activity when mutated. These results will facilitate the optimisation of endonuclease inhibitors as potential new anti-influenza drugs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dias, Alexandre -- Bouvier, Denis -- Crepin, Thibaut -- McCarthy, Andrew A -- Hart, Darren J -- Baudin, Florence -- Cusack, Stephen -- Ruigrok, Rob W H -- England -- Nature. 2009 Apr 16;458(7240):914-8. doi: 10.1038/nature07745. Epub 2009 Feb 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS, UMR 5233, 6 rue Jules Horowitz, BP181, 38042 Grenoble Cedex 9, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19194459" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Catalytic Domain ; Endonucleases/chemistry/*metabolism ; Enzyme Stability ; Histidine/metabolism ; Humans ; Influenza A Virus, H3N2 Subtype/*enzymology ; Influenza A Virus, H5N1 Subtype/enzymology ; Influenzavirus C/enzymology ; Manganese/metabolism/pharmacology ; Models, Molecular ; Molecular Sequence Data ; Protein Subunits/*chemistry/*metabolism ; RNA Caps/*metabolism ; RNA Replicase/*chemistry/*metabolism ; Viral Proteins/*chemistry/*metabolism
    Print ISSN: 0028-0836
    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Publikationsdatum: 2009-12-25
    Beschreibung: The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors in EGFR-mutant non-small-cell lung cancer (NSCLC) is limited by the development of drug-resistance mutations, including the gatekeeper T790M mutation. Strategies targeting EGFR T790M with irreversible inhibitors have had limited success and are associated with toxicity due to concurrent inhibition of wild-type EGFR. All current EGFR inhibitors possess a structurally related quinazoline-based core scaffold and were identified as ATP-competitive inhibitors of wild-type EGFR. Here we identify a covalent pyrimidine EGFR inhibitor by screening an irreversible kinase inhibitor library specifically against EGFR T790M. These agents are 30- to 100-fold more potent against EGFR T790M, and up to 100-fold less potent against wild-type EGFR, than quinazoline-based EGFR inhibitors in vitro. They are also effective in murine models of lung cancer driven by EGFR T790M. Co-crystallization studies reveal a structural basis for the increased potency and mutant selectivity of these agents. These mutant-selective irreversible EGFR kinase inhibitors may be clinically more effective and better tolerated than quinazoline-based inhibitors. Our findings demonstrate that functional pharmacological screens against clinically important mutant kinases represent a powerful strategy to identify new classes of mutant-selective kinase inhibitors.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2879581/" 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/PMC2879581/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhou, Wenjun -- Ercan, Dalia -- Chen, Liang -- Yun, Cai-Hong -- Li, Danan -- Capelletti, Marzia -- Cortot, Alexis B -- Chirieac, Lucian -- Iacob, Roxana E -- Padera, Robert -- Engen, John R -- Wong, Kwok-Kin -- Eck, Michael J -- Gray, Nathanael S -- Janne, Pasi A -- P50CA090578/CA/NCI NIH HHS/ -- R01 CA122794/CA/NCI NIH HHS/ -- R01 CA130876/CA/NCI NIH HHS/ -- R01 CA130876-02/CA/NCI NIH HHS/ -- R01 CA135257/CA/NCI NIH HHS/ -- R01AG2400401/AG/NIA NIH HHS/ -- R01CA080942/CA/NCI NIH HHS/ -- R01CA11446/CA/NCI NIH HHS/ -- R01CA116020/CA/NCI NIH HHS/ -- R01CA130876-02/CA/NCI NIH HHS/ -- R01CA135257/CA/NCI NIH HHS/ -- R01GM070590/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Dec 24;462(7276):1070-4. doi: 10.1038/nature08622.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cancer Biology, Dana-Farber Cancer Institute, 44 Binney Street, Boston, Massachusetts 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20033049" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antineoplastic Agents/chemistry/*pharmacology/toxicity ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Drug Evaluation, Preclinical ; Drug Resistance, Neoplasm/genetics ; Lung/drug effects ; Mice ; Models, Chemical ; Models, Molecular ; Mutation/*genetics ; NIH 3T3 Cells ; Phosphorylation/drug effects ; Protein Kinase Inhibitors/chemistry/*pharmacology/toxicity ; Receptor, Epidermal Growth Factor/*antagonists & inhibitors/*genetics
    Print ISSN: 0028-0836
    Digitale ISSN: 1476-4687
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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