1ctn
From Proteopedia
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CRYSTAL STRUCTURE OF A BACTERIAL CHITINASE AT 2.3 ANGSTROMS RESOLUTION
Overview
BACKGROUND: Chitinases cleave the beta-1-4-glycosidic bond between the, N-acetyl-D-glucosamine units of which chitin is comprised. Chitinases are, present in plants, bacteria and fungi, but whereas structures are, available for two prototypic plant enzymes, no structure is available for, a bacterial or fungal chitinase. RESULTS: To redress this imbalance, the, structure of native chitinase A from Serratia marcescens has been solved, by multiple isomorphous replacement and refined at 2.3 A resolution, resulting in a crystallographic R-factor of 16.2%. The enzyme comprises, three domains: an all beta-strand amino-terminal domain, a catalytic, alpha/beta-barrel domain, and a small alpha+beta-fold domain. There are, several residues with unusual geometries in the structure. Structure, determination of chitinase A in complex with, N,N',N",N"'-tetra-acetylo-chitotetraose, together with biochemical and, sequence analysis data, enabled the positions of the active-site and, catalytic residues to be proposed. CONCLUSIONS: The reaction mechanism, seems to be similar to that of lysozyme and most other glycosylhydrolases, i.e. general acid-base catalysis. The role of the amino-terminal domain, could not be identified, but it has similarities to the fibronectin III, domain. This domain may possibly facilitate the interaction of chitinase A, with chitin.
About this Structure
1CTN is a Single protein structure of sequence from Serratia marcescens. Active as Chitinase, with EC number 3.2.1.14 Full crystallographic information is available from OCA.
Reference
Crystal structure of a bacterial chitinase at 2.3 A resolution., Perrakis A, Tews I, Dauter Z, Oppenheim AB, Chet I, Wilson KS, Vorgias CE, Structure. 1994 Dec 15;2(12):1169-80. PMID:7704527
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