2vgk

Crystal structure of Actinomadura R39 DD-peptidase complexed with a peptidoglycan-mimetic cephalosporin

spinqualitylabelsall models 2vgk, resolution 2.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vgk is a 4 chain structure with sequence from Actinomadura sp.. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MG, REZ, SO4 Related: 1w79, 1w8q, 2vgj, 1w8y Activity: Serine-type D-Ala-D-Ala carboxypeptidase, with EC number 3.4.16.4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [DAC_ACTSP] Removes C-terminal D-alanyl residues from sugar-peptide cell wall precursors. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The X-ray crystal structures of covalent complexes of the Actinomadura R39 dd-peptidase and Escherichia coli penicillin-binding protein (PBP) 5 with beta-lactams bearing peptidoglycan-mimetic side chains have been determined. The structure of the hydrolysis product of an analogous peptide bound noncovalently to the former enzyme has also been obtained. The R39 DD-peptidase structures reveal the presence of a specific binding site for the D-alpha-aminopimelyl side chain, characteristic of the stem peptide of Actinomadura R39. This binding site features a hydrophobic cleft for the pimelyl methylene groups and strong hydrogen bonding to the polar terminus. Both of these active site elements are provided by amino acid side chains from two separate domains of the protein. In contrast, no clear electron density corresponding to the terminus of the peptidoglycan-mimetic side chains is present when these beta-lactams are covalently bound to PBP5. There is, therefore, no indication of a specific side-chain binding site in this enzyme. These results are in agreement with those from kinetics studies published earlier and support the general prediction made at the time of a direct correlation between kinetics and structural evidence. The essential high-molecular-mass PBPs have demonstrated, to date, no specific reactivity with peptidoglycan-mimetic peptide substrates and beta-lactam inhibitors and, thus, probably do not possess a specific substrate-binding site of the type demonstrated here with the R39 DD-peptidase. This striking deficiency may represent a sophisticated defense mechanism against low-molecular-mass substrate-analogue inhibitors/antibiotics; its discovery should focus new inhibitor design. Crystal structures of complexes of bacterial DD-peptidases with peptidoglycan-mimetic ligands: the substrate specificity puzzle.,Sauvage E, Powell AJ, Heilemann J, Josephine HR, Charlier P, Davies C, Pratt RF J Mol Biol. 2008 Aug 29;381(2):383-93. Epub 2008 Jun 10. PMID:18602645 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Carboxypeptidase 3D structures Penicillin-binding protein 3D structures

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