This domain represents the N terminal domain in chitobiases andbeta-hexosaminidases EC:3.2.1.52. It is composed of a betasandwich structure that is similar in structure to the cellulosebinding domain of cellulase from Cellulomonas fimi [1]. Thissuggests that this may be a carbohydrate binding domain. Putative carbohydrate binding domain CHB_HEX