InterPro: IPR015922 Carbohydrate-binding domain, family 9-like, subgroup

This entry represents a family 9 carbohydrate-binding module (CBD9)-like domain found in both CBD9 proteins such as endo-1,4-beta-xylanase (EC:3.2.1.8), as well as a C-terminal domain in the glucodextranase family of proteins (EC:3.2.1.70). The CBD9-like domain assumes an immunoglobulin-like beta-sandwich fold, with an additional beta-strand at the N terminus [1].

Bacterial extracellular cellulases and hemicellulases are involved in the hydrolysis of the major structural polysaccharides of plant cell walls. These are usually modular enzymes that contain catalytic and non-catalytic domains. The CBD9 domain binds to cellulose, xylan, as well as to a range of soluble di- and mono-saccharides, and is found in cellulose- and xylan-degrading enzymes [2].

Glucodextranase hydrolyzes alpha-1,6-glucosidic linkages of dextran from the non-reducing end to produce beta-D-glucose via an inverting reaction mechanism and classified into the glycoside hydrolase family 15 (GH15) [3].