Carbohydrate-binding modules CBMs

Many glycosidases which attack insoluble or partly soluble polysaccharides have a modular construction, in which catalytic domains and carbohydrate binding modules (CBMs) are produced in the same polypeptide. Although there may be occasional exceptions, the main function of these domains appears to be to increase the local concentration of enzyme by loosely absorbing the enzyme to the substrate. CBMs have been classified into families on the basis of amino acid sequence, like the catalytic domains and are on CAZy, the continuously updated website in summer 2007 there were 49 families. Early work had concentrated on the cellulose binding domains (CBDs) previous classifications had referred to CBM (or CBD) Types and used Roman numerals and, to concur with this usage, CBM Families 1-13 are the same as CBM Types 1-XIII. 

Ribeiro, T Ponte, PIP Guerreiro, CIPD Santos, HM Falcatildeo, L Freire, JPB et al. A family 11 carbohydrate-binding module (CBM) improves the efficacy of a recombinant cellulase used to supplement barley-based diets for broilers at lower dosage rates. British Poultry Science, 2008, 49(5), 600-8. 

Xu, Q Song, Q Ai, X McDonald, TJ Long, H Ding, S et al. Engineered carbohydrate-binding module (CBM) protein-suspended single-walled carbon nanotubes in water. Chem Commun., 2009, 337-9. 

Both enzymes have a family 1 CBM however, they differ in that the carbohydrate binding module is N-terminal in FaeA and C-terminal in FaeB (Fig 1). This situation mirrors that of Cel6A (N-terminal CBM) and Cel7A (C-terminal CBM) of T. reesei. The... 

Clostridium thermocellum s cellulosome. CBM carbohydrate-binding module (Based on Gilbert 2007)... 

More than 300 proteins are currently classified in the CAZy database, including glycoside hydrolases (GHs), glicosyltransferases (GTs), polysaccharide lyases (PLs) and carbohydrate esterases (CEs). Usually, CAZymes present a modular structure, nearly 7% of the enzymes having at least one carbohydrate-binding module [13]. CBMs are also classified... 

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