Structure of the Endoglucanase I from Fusarium oxysporum : Native, Cellobiose, and 3,4-Epoxybutyl β- d -Cellobioside-Inhibited Forms, at 2.3 Å Resolution

Gerlind Sulzenbacher (1) , Martin Schülein , Gideon J Davies (1)

1 Department of Chemistry [York, UK]

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 Å resolution. In addition to the native enzyme, structures have also been determined with both the affinity label, 3,4epoxybutyl-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

Domaines: Biologie structurale [q-bio.BM]; Mycologie

Gerlind Sulzenbacher, Martin Schülein, Gideon J Davies. Structure of the Endoglucanase I from Fusarium oxysporum : Native, Cellobiose, and 3,4-Epoxybutyl β- d -Cellobioside-Inhibited Forms, at 2.3 Å Resolution. Biochemistry, 1997, 36 (19), pp.5902-5911. ⟨10.1021/bi962963+⟩. ⟨hal-03160743⟩