Homologous Superfamily

CBM2, carbohydrate-binding domain superfamily (IPR012291)

Short name: CBM2_carb-bd_dom_sf

Overlapping entries


The microbial degradation of cellulose and xylans requires several types of enzyme such as endoglucanases (EC, cellobiohydrolases (EC (exoglucanases), or xylanases (EC [PMID: 1886523]. Structurally, cellulases and xylanases generally consist of a catalytic domain and a conserved region of ~100 amino acid residues, the carbohydrate-binding module 2 (CBM2) [PMID: 1812490]. It is found either at the N-terminal or at the C-terminal extremity of these enzymes.

CBM2 can be classified in 2 subfamilies according to substrate specificities: CBM2a which binds cellulose and CBM2b which interacts specifically with xylan. Like other CBM domains CBM2 is a beta-sheet domain containing a planar face which interacts with its ligand via a hydrophobic strip of aromatic residues [PMID: 7766609]. In family 2a this hydrophobic surface consists of three tryptophan residues, which are all required for binding soluble and insoluble forms of cellulose [PMID: 9662439]. In family 2b only 2 surface-exposed tryptophans are conserved and the first one is oriented differently. It is therefore not well oriented to interact with cellulose but is ideal for binding xylan [PMID: 10425686].

This entry recognises both CBM2 subfamilies.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004553 hydrolase activity, hydrolyzing O-glycosyl compounds
GO:0030247 polysaccharide binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.