25 research outputs found

    Crystallization and preliminary crystallographic data of the PAS domain of the NifL protein from Azotobacter vinelandii.

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    The Azotobacter vinelandii NifL protein is a redox-sensing flavoprotein which inhibits the activity of the nitrogen-specific transcriptional activator NifA. The N-terminal PAS domain has been overexpressed in Escherichia coli and crystallized by the hanging-drop vapour-diffusion method. The crystal belongs to the rhombohedral space group R32, with unit-cell parameters a = b = 65.0, c = 157.3 Å, and has one molecule in the asymmetric unit. Native data were collected to 3.0 Å on the BW7B synchrotron beamline at the EMBL Hamburg Outstation

    Characteristics and outcomes of patients requiring rapid response system activation within 24 hours of emergency admission

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    Objectives:&nbsp;To establish the prevalence of emergency responses for clinical deterioration (cardiac arrest team or medical emergency team [MET] activation) within 24 hours of emergency admission, and determine if there were differences in characteristics and outcomes of ward patients whose emergency response was within, or beyond, 24 hours of emergency admission. Design, setting and participants: A retrospective, descriptive, exploratory study using MET, cardiac arrest, emergency department and inpatient databases, set in a 365-bed urban district hospital in Melbourne, Australia. Participants were adult hospital inpatients admitted to a medical or surgical ward via the emergency department (ED) who needed an emergency response for clinical deterioration during 2012. Main outcome measures: Inhospital mortality, unplanned intensive care unit admission and hospital length of stay (LOS). Results: A total of 819 patients needed an emergency response for clinical deterioration: 587 patients were admitted via the ED and 28.4% of emergency responses occurred within 24 hours of emergency admission. Patients whose first emergency response was within 24 hours of emergency admission (compared with beyond 24 hours) were more likely to be triaged to Australasian triage scale category 1 (5.4% v 1.2%, P=0.005), less likely to require ICU admission after the emergency response (7.6% v 13.9%, P=0.039), less likely to have recurrent emergency responses during their hospital stay (9.7% v 34%, P &lt; 0.001) and had a shorter median hospital LOS (7 days v 11 days, P &lt; 0.001). Conclusions: One-quarter of emergency responses after admission via the ED occurred within 24 hours. Further research is needed to understand the predictors of deterioration in patients needing emergency admission.</div

    Outcome of the First wwPDB/CCDC/D3R Ligand Validation Workshop.

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    Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank (PDB) archive, ∼75% include at least one non-polymeric ligand. Ligand geometrical and stereochemical quality, the suitability of ligand models for in silico drug discovery and design, and the goodness-of-fit of ligand models to electron-density maps vary widely across the archive. We describe the proceedings and conclusions from the first Worldwide PDB/Cambridge Crystallographic Data Center/Drug Design Data Resource (wwPDB/CCDC/D3R) Ligand Validation Workshop held at the Research Collaboratory for Structural Bioinformatics at Rutgers University on July 30-31, 2015. Experts in protein crystallography from academe and industry came together with non-profit and for-profit software providers for crystallography and with experts in computational chemistry and data archiving to discuss and make recommendations on best practices, as framed by a series of questions central to structural studies of macromolecule-ligand complexes. What data concerning bound ligands should be archived in the PDB? How should the ligands be best represented? How should structural models of macromolecule-ligand complexes be validated? What supplementary information should accompany publications of structural studies of biological macromolecules? Consensus recommendations on best practices developed in response to each of these questions are provided, together with some details regarding implementation. Important issues addressed but not resolved at the workshop are also enumerated.The workshop was supported by funding to RCSB PDB by the National Science Foundation (DBI 1338415); PDBe by the Wellcome Trust (104948); PDBj by JST-NBDC; BMRB by the National Institute of General Medical Sciences (GM109046); D3R by the National Institute of General Medical Sciences (GM111528); registration fees from industrial participants; and tax-deductible donations to the wwPDB Foundation by the Genentech Foundation and the Bristol-Myers Squibb Foundation.This is the final version of the article. It first appeared from Cell Press via https://doi.org//10.1016/j.str.2016.02.01

    Deposit3D: a tool for automating structure depositions to the Protein Data Bank

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    This paper describes a Python script that may be used to gather all required structure-annotation information into an mmCIF file for upload through the RCSB PDB ADIT structure-deposition interface

    Crystallographic and enzymatic investigations on the role of Ser558, His610, and Asn614 in the catalytic mechanism of Azotobacter vinelandii dihydrolipoamide acetyltransferase (E2p)

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    Dihydrolipoamide acetyltransferase (E2p) is the structural and catalytic core of the pyruvate dehydrogenase multienzyme complex. In Azotobacter vinelandii E2p, residues Ser558, His610', and Asn614' are potentially involved in transition state stabilization, proton transfer, and activation of proton transfer, respectively. Three active site mutants, S558A, H610C, and N614D, of the catalytic domain of A. vinelandii E2p were prepared by site-directed mutagenesis and enzymatically characterized. The crystal structures of the three mutants have been determined at 2.7, 2.5, and 2.6 A resolution, respectively. The S558A and H610C mutants exhibit a strongly (200-fold and 500-fold, respectively) reduced enzymatic activity whereas the substitution of Asn614' by aspartate results in a moderate (9-fold) reduced activity. The decrease in enzymatic activity of the S558A and H610C mutants is solely due to the absence of the hydroxyl and imidazole side chains, respectively, and not due to major conformational rearrangements of the protein. Furthermore the sulfhydryl group of Cys610' is reoriented, resulting in a completely buried side chain which is quite different from the solvent-exposed imidazole group of His610' in the wild-type enzyme. The presence of Asn614' in A. vinelandii E2p is exceptional since all other 18 known dihydrolipoamide acyltransferase sequences contain an aspartate in this position. We observe no difference in conformation of Asp614' in the N614D mutant structure compared with the conformation of Asn614' in the wild-type enzyme. Detailed analysis of all available structures and sequences suggests two classes of acetyltransferases: one class with a catalytically essential His-Asn pair and one with a His-Asp-Arg triad as present in chloramphenicol acetyltransferase [Leslie, A. G. W. (1990) J. Mol. Biol. 213, 167-186] and in the proposed active site models of Escherichia coli and yeast E2p
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