This enzyme belongs to Glycosidase family-6, more specifically the exoglucanase family, which requires polymer-chain ends for catalytic activity. It has an inverting mechanism (equatorial to axial conformation) and catalyses the hydrolysis of (1-->4)-beta-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains.
Defined by 6 residues: TYR:B-85 [auth B-169]ARG:B-90 [auth B-174]ASP:B-91 [auth B-175]SER:B-97 [auth B-181]ASP:B-137 [auth B-221]ASP:B-317 [auth B-401]