PROSITE documentation PDOC51763 [for PROSITE entry PS51763]

CBM10 (carbohydrate binding type-10) domain profile

Plant cell wall hydrolases generally have a modular structure consisting of a catalytic domain linked to one or more noncatalytic carbohydrate-binding modules (CBMs). The majority of these CBMs interact with cellulose and are thus referred to as cellulose-binding domains or CBDs. CBM10s are small molecules, comprising only ca. 45 residues, that bind to insoluble forms of cellulose [E1]. CBM10s contain three tryptophan and two tyrosine residues which are completely conserved. The CBM10 domain is found in xylanases, mannanases and cellulases from aerobic bacteria and anaerobic fungi [1,2,3,4].

The CBM10 domain consists of two antiparallel β-sheets, one with two strands and one with three, with a short α-helix across one face of the three-stranded sheet (see <PDB:1QLD>) [2,4].

Some proteins known to contain a CBM10 domain are listed below:

• Cellvibrio japonicus endo-1,4-β-xylanase A (xynA), endohydrolyses (1->4)-β-D-xylosidic linkages in xylans.
• Cellvibrio japonicus bifunctional xylanase/xylan deacetylase (xyn11A), endo-acting xylanase which specifically cleaves internal linkages on the xylan backbone, releasing xylooligosaccharides.
• Cellvibrio japonicus endoglucanase A (celA), endohydrolyses (1->4)-β-D- glucosidic linkages in cellulose, lichenin and cereal β-D-glucans.
• Cellvibrio japonicus endoglucanase B (celB), catalyzes the endohydrolysis of 1,4-β-glucosidic linkages in cellulose, lichenin and cereal β-D- glucans.
• Cellvibrio japonicus endoglucanase C (celC), endohydrolyses (1->4)-β-D- glucosidic linkages in cellulose, lichenin and cereal β-D-glucans.
• Neocallimastix patriciarum (Rumen fungus) endoglucanase B (CELB), endohydrolyse (1->4)-β-D-glucosidic linkages in cellulose, lichenin and cereal β-D-glucans.
• Neocallimastix patriciarum (Rumen fungus) bifunctional endo-1,4-β- xylanase A (XYNA), hydrolyzes xylans into xylobiose and xylose.
• Piromyces sp. endo-1,4-β-xylanase A (XYNA), hydrolyzes 1,4-β linked polysaccharide backbones of xylans, one of the major hemicellulose components in hardwoods and softwoods.
• Piromyces sp. mannan endo-1,4-β-mannosidase A (MANA), hydrolyzes 1,4- β linked polysaccharide backbones of mannans, one of the major hemicellulose components in hardwoods and softwoods.

The profile we developed covers the entire CBM10 domain.