Structure of the endoglucanase I from Fusarium oxysporum: native, cellobiose, and 3,4-epoxybutyl beta-D-cellobioside-inhibited forms, at 2.3 A resolution.
Primary Citation of Related Structures: 2OVW, 3OVW, 4OVW
PubMed Abstract:
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 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.
Related Citations:
Structure of the Fusarium Oxysporum Endoglucanase I with a Nonhydrolyzable Substrate Analogue: Substrate Distortion Gives Rise to the Preferred Axial Orientation for the Leaving Group Sulzenbacher, G., Driguez, H., Henrissat, B., Schulein, M., Davies, G.J. (1996) Biochemistry 35: 15280
The Use of Conserved Cellulase Family-Specific Sequences to Clone Cellulase Homologue Cdnas from Fusarium Oxysporum Sheppard, P.O., Grant, F.J., Oort, P.J., Sprecher, C.A., Foster, D.C., Hagen, F.S., Upshall, A., Mcknight, G.L., O'Hara, P.J. (1994) Gene 150: 163
Organizational Affiliation:
Department of Chemistry, University of York, Heslington, U.K.
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