1zrs

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spinqualitylabelsall models 1zrs, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

wild-type LD-carboxypeptidase

Overview

LD-Carboxypeptidases (EC 3.4.17.13) are named for their ability to cleave, amide bonds between l- and d-amino acids, which occur naturally in, bacterial peptidoglycan. They are specific for the link between, meso-diaminopimelic acid and d-alanine and therefore degrade GlcNAc-MurNAc, tetrapeptides to the corresponding tripeptides. As only the tripeptides, can be reused as peptidoglycan building blocks, ld-carboxypeptidases are, thought to play a role in peptidoglycan recycling. Despite the, pharmaceutical interest in peptidoglycan biosynthesis, the fold and, catalytic type of ld-carboxypeptidases are unknown. Here, we show that a, previously uncharacterized open reading frame in Pseudomonas aeruginosa, has ld-carboxypeptidase activity and present the crystal structure of this, enzyme. The structure shows that the enzyme consists of an N-terminal, beta-sheet and a C-terminal beta-barrel domain. At the interface of the, two domains, Ser(115) adopts a highly strained conformation in the context, of a strand-turn-helix motif that is similar to the "nucleophilic elbow", in alphabeta-hydrolases. Ser(115) is hydrogen-bonded to a histidine, residue, which is oriented by a glutamate residue. All three residues, which occur in the order Ser-Glu-His in the amino acid sequence, are, strictly conserved in naturally occurring ld-carboxypeptidases and cannot, be mutated to alanines without loss of activity. We conclude that, ld-carboxypeptidases are serine peptidases with Ser-His-Glu catalytic, triads.

About this Structure

1ZRS is a Single protein structure of sequence from Pseudomonas aeruginosa. Active as Muramoyltetrapeptide carboxypeptidase, with EC number 3.4.17.13 Full crystallographic information is available from OCA.

Reference

Pseudomonas aeruginosa LD-carboxypeptidase, a serine peptidase with a Ser-His-Glu triad and a nucleophilic elbow., Korza HJ, Bochtler M, J Biol Chem. 2005 Dec 9;280(49):40802-12. Epub 2005 Sep 14. PMID:16162494

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