The enzyme removes XXXG heptasaccharides, XXLG/XLXG octasaccharides and XLLG nonasaccharides from the end of tamarind seed xyloglucan polymers in a processive manner. Hydrolysis occurs at the unsubstituted?D-glucopyranose residue in the main backbone. It is not known whether the cleavage takes place at the reducing or non-reducing end of the polymer. Very low activity with ¦Â-D-glucans. The enzyme from?Chrysosporium lucknowense?shifts to an endoglucanase mode when acting on linear substrates without bulky substituents on the polymeric backbone such as barley ¦Â-glucan. Formerly EC?3.2.1.160.
Cofactor
History
Reactions
Hydrolysis of (1->4)-D-glucosidic linkages in xyloglucans so as to successively remove oligosaccharides from the chain end