2ovw

From Proteopedia

Revision as of 16:31, 5 November 2007

ENDOGLUCANASE I COMPLEXED WITH CELLOBIOSE

Overview

The mechanisms involved in the enzymatic degradation of cellulose are of, great ecological and commercial importance. The breakdown of cellulose by, fungal species is performed by a consortium of free enzymes, known as, cellobiohydrolases and endoglucanases, which are found in many of the 57, glycosyl hydrolase families. The structure of the endoglucanase I (EG I), found in glycosyl hydrolase family 7, from the thermophilic fungus, Fusarium oxysporum has been solved at 2.3 A resolution. In addition to the, native enzyme, structures have also been determined with both the affinity, label, 3,4-epoxybutyl beta-D-cellobioside, and the reaction product, cellobiose. The affinity label is covalently bound, as expected, to the, catalytic nucleophile, Glu197, with clear evidence for binding of both the, R and S stereoisomers. Cellobiose is found bound to the -2 and -1 subsites, of the enzyme. In marked contrast to the structure of EG I with a, nonhydrolyzable thiosaccharide analog, which spanned the -2, -1, and +1, subsites and which had a skew-boat conformation for the -1 subsite sugar, [Sulzenbacher, G., et al. (1996) Biochemistry 35, 15280-15287], the, cellobiose complex shows no pyranoside ring distortion in the -1 subsite, implying that strain is induced primarily by the additional +1 subsite, interactions and that the product is found, as expected, in its unstrained, conformation.

About this Structure

2OVW is a Single protein structure of sequence from Fusarium oxysporum with NAG and CBI as ligands. Active as Cellulase, with EC number 3.2.1.4 Structure known Active Sites: CTA, CTB, CTC and CTD. Full crystallographic information is available from OCA.

Reference

Structure of the endoglucanase I from Fusarium oxysporum: native, cellobiose, and 3,4-epoxybutyl beta-D-cellobioside-inhibited forms, at 2.3 A resolution., Sulzenbacher G, Schulein M, Davies GJ, Biochemistry. 1997 May 13;36(19):5902-11. PMID:9153432

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