Protein Data Bank is a repository for 3-D biological macromolecular structure.All data are available to the public.It includes proteins, nucleic acids and viruses.Obtained by X-Ray crystallography (80%) or NMR spectroscopy (16%).Submitted by biologists and biochemists from around the world.Founded in 1971 by Brookhaven National Laboratory, New York.First set of data were entered on punched cards. Then with magnetic tapes.Transferred to the Research Collaborators for Structural Bioinformatics (RCSB) in 1998.Currently it holds 29,000 released structures.PDB is an important resource for research in the academic,pharmaceutical,and biotechnology sectors,
Structural basis for effectiveness of siderophore-conjugated monocarbams against clinically relevant strains of Pseudomonas aeruginosa.
(2010) Proc.Natl.Acad.Sci.USA
Crystal structure of the leucine aminopeptidase from Pseudomonas putida reveals the molecular basis for its enantioselectivity and broad substrate specificity.
(2010) J.Mol.Biol.398: 703-714
PubMed Abstract:
The zinc-dependent leucine aminopeptidase from Pseudomonas putida (ppLAP) is an important enzyme for the industrial production of enantiomerically pure amino acids. To provide a better understanding of its structure-function relationships, the enzyme was studied by X-ray crystallography. Crystal structures of native ppLAP at pH 9.5 and pH 5.2, and in complex with the inhibitor bestatin, show that the overall folding and hexameric organization of ppLAP are very similar to those of the closely related di-zinc leucine aminopeptidases (LAPs) from bovine lens and Escherichia coli. At pH 9.5, the active site contains two metal ions, one identified as Mn(2+) or Zn(2+) (site 1), and the other as Zn(2+) (site 2). By using a metal-dependent activity assay it was shown that site 1 in heterologously expressed ppLAP is occupied mainly by Mn(2+). Moreover, it was shown that Mn(2+) has a significant activation effect when bound to site 1 of ppLAP. At pH 5.2, the active site of ppLAP is highly disordered and the two metal ions are absent, most probably due to full protonation of one of the metal-interacting residues, Lys267, explaining why ppLAP is inactive at low pH. A structural comparison of the ppLAP-bestatin complex with inhibitor-bound complexes of bovine lens LAP, along with substrate modelling, gave clear and new insights into its substrate specificity and high level of enantioselectivity.
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