2his
From Proteopedia
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CELLULOMONAS FIMI XYLANASE/CELLULASE DOUBLE MUTANT E127A/H205N WITH COVALENT CELLOBIOSE
Overview
The catalytic mechanism of 'retaining' beta-glycosidases has been the, subject of considerable interest and debate for many years. The, visualization of a covalent glycosyl enzyme intermediate by X-ray, crystallography was first accomplished with a saccharide substrate, substituted with fluorine at its 2-position. The structure implicated, major roles for residue His 205 and for the 2-hydroxyl position of the, proximal saccharide in binding and catalysis. Here we have studied the, kinetic behavior of various His 205 mutants. One of these mutants, a, double mutant H205N/E127A, has been used to stabilize a covalent, glycosyl-enzyme intermediate involving an unsubstituted sugar, permitting, crystallographic analysis of the interactions between its 2-hydroxyl group, and the enzyme.
About this Structure
2HIS is a Single protein structure of sequence from Cellulomonas fimi. Active as Cellulose 1,4-beta-cellobiosidase, with EC number 3.2.1.91 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Insights into transition state stabilization of the beta-1,4-glycosidase Cex by covalent intermediate accumulation in active site mutants., Notenboom V, Birsan C, Nitz M, Rose DR, Warren RA, Withers SG, Nat Struct Biol. 1998 Sep;5(9):812-8. PMID:9731776
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