The thermostabilizing domain, XynA, of Caldibacillus cellulovorans xylanase is a xylan binding domain

We show that the N-terminal 'thermostabilizing domain ' (TSD) of the xylana se, XynA, from the thermophilic bacterium Caldibacillus cellulovorans also acts as a xylan binding domain. Affinity electrophoresis experiments show t hat this TSD selectively binds soluble xylan and binds weakly to hydroxyeth ylcellulose. Based on this, and previously reported evidence, we propose th at xylanase-associated TSDs are xylan binding domains.