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</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/ | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1hd8 ConSurf]. | ||
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Revision as of 09:16, 9 February 2016
CRYSTAL STRUCTURE OF A DEACYLATION-DEFECTIVE MUTANT OF PENICILLIN-BINDING PROTEIN 5 AT 2.3 A RESOLUTIONCRYSTAL STRUCTURE OF A DEACYLATION-DEFECTIVE MUTANT OF PENICILLIN-BINDING PROTEIN 5 AT 2.3 A RESOLUTION
Structural highlights
Function[DACA_ECOLI] 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 PubMedPenicillin-binding protein 5 (PBP 5) of Escherichia coli functions as a d-alanine carboxypeptidase, cleaving the C-terminal d-alanine residue from cell wall peptides. Like all PBPs, PBP 5 forms a covalent acyl-enzyme complex with beta-lactam antibiotics; however, PBP 5 is distinguished by its high rate of deacylation of the acyl-enzyme complex (t(12) approximately 9 min). A Gly-105 --> Asp mutation in PBP 5 markedly impairs this beta-lactamase activity (deacylation), with only minor effects on acylation, and promotes accumulation of a covalent complex with peptide substrates. To gain further insight into the catalytic mechanism of PBP 5, we determined the three-dimensional structure of the G105D mutant form of soluble PBP 5 (termed sPBP 5') at 2.3 A resolution. The structure is composed of two domains, a penicillin binding domain with a striking similarity to Class A beta-lactamases (TEM-1-like) and a domain of unknown function. In addition, the penicillin-binding domain contains an active site loop spatially equivalent to the Omega loop of beta-lactamases. In beta-lactamases, the Omega loop contains two amino acids involved in catalyzing deacylation. This similarity may explain the high beta-lactamase activity of wild-type PBP 5. Because of the low rate of deacylation of the G105D mutant, visualization of peptide substrates bound to the active site may be possible. Crystal structure of a deacylation-defective mutant of penicillin-binding protein 5 at 2.3-A resolution.,Davies C, White SW, Nicholas RA J Biol Chem. 2001 Jan 5;276(1):616-23. PMID:10967102[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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