3OVW

ENDOGLUCANASE I NATIVE STRUCTURE

Summary for 3OVW

• Entry DOI: 10.2210/pdb3ovw/pdb
• Descriptor: ENDOGLUCANASE I, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: glycosyl hydrolase, endoglucanase i, glycosylated protein, hydrolase
• Biological source: Fusarium oxysporum
• Total number of polymer chains: 2
• Total formula weight: 90255.47

Authors

Davies, G.J.,Schulein, M. (deposition date: 1997-10-06, release date: 1998-04-08, Last modification date: 2024-10-30)

Primary citation

Sulzenbacher, G.,Schulein, M.,Davies, G.J.
Structure of the endoglucanase I from Fusarium oxysporum: native, cellobiose, and 3,4-epoxybutyl beta-D-cellobioside-inhibited forms, at 2.3 A resolution.
Biochemistry, 36:5902-5911, 1997

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 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.

PubMed: 9153432
DOI: 10.1021/bi962963+

Experimental method

X-RAY DIFFRACTION (2.3 Å)