1ei5

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spinqualitylabelsall models 1ei5, resolution 1.9Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF A D-AMINOPEPTIDASE FROM OCHROBACTRUM ANTHROPI

Overview

BACKGROUND: beta-Lactam compounds are the most widely used antibiotics., They inactivate bacterial DD-transpeptidases, also called, penicillin-binding proteins (PBPs), involved in cell-wall biosynthesis., The most common bacterial resistance mechanism against beta-lactam, compounds is the synthesis of beta-lactamases that hydrolyse beta-lactam, rings. These enzymes are believed to have evolved from cell-wall, DD-peptidases. Understanding the biochemical and mechanistic features of, the beta-lactam targets is crucial because of the increasing number of, resistant bacteria. DAP is a D-aminopeptidase produced by Ochrobactrum, anthropi. It is inhibited by various beta-lactam compounds and shares, approximately 25% sequence identity with the R61 DD-carboxypeptidase and, the class C beta-lactamases. RESULTS: The crystal structure of DAP has, been determined to 1.9 A resolution using the multiple isomorphous, replacement (MIR) method. The enzyme folds into three domains, A, B and C., Domain A, which contains conserved catalytic residues, has the classical, fold of serine beta-lactamases, whereas domains B and C are both, antiparallel eight-stranded beta barrels. A loop of domain C protrudes, into the substrate-binding site of the enzyme. CONCLUSIONS: Comparison of, the biochemical properties and the structure of DAP with PBPs and serine, beta-lactamases shows that although the catalytic site of the enzyme is, very similar to that of beta-lactamases, its substrate and inhibitor, specificity rests on residues of domain C. DAP is a new member of the, family of penicillin-recognizing proteins (PRPs) and, at the present time, its enzymatic specificity is clearly unique.

About this Structure

1EI5 is a Single protein structure of sequence from Ochrobactrum anthropi. Active as D-stereospecific aminopeptidase, with EC number 3.4.11.19 Full crystallographic information is available from OCA.

Reference

Crystal structure of a D-aminopeptidase from Ochrobactrum anthropi, a new member of the 'penicillin-recognizing enzyme' family., Bompard-Gilles C, Remaut H, Villeret V, Prange T, Fanuel L, Delmarcelle M, Joris B, Frere J, Van Beeumen J, Structure. 2000 Sep 15;8(9):971-80. PMID:10986464

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