CBD_II

CBD_II
SMART accession number:SM00637
Description: -
Interpro abstract (IPR001919):

The microbial degradation of cellulose and xylans requires several types of enzyme such as endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) (exoglucanases), or xylanases (EC 3.2.1.8) [(PUBMED: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) [(PUBMED: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 [(PUBMED:7766609)]. In family 2a this hydrophobic surface consists of three tryptophan residues, which are all required for binding soluble and insoluble forms of cellulose [(PUBMED: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 [(PUBMED:10425686)].

This domain recognises both CBM2 subfamilies.

GO process:carbohydrate metabolic process (GO:0005975)
GO function:hydrolase activity, hydrolyzing O-glycosyl compounds (GO:0004553), carbohydrate binding (GO:0030246)
Family alignment:
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There are 14472 CBD_II domains in 14006 proteins in SMART's nrdb database.

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