Carbohydrate Binding Module family 35 (CBM35); appended mainly to enzymes that bind alpha-D-galactose (CBM35-Gal), including glycoside hydrolase (GH) families GH27 and GH43.
This family includes carbohydrate binding module family 35 (CBM35); these are non-catalytic carbohydrate binding domains that are appended mainly to enzymes that bind alpha-D-galactose (CBM35-Gal), including glycoside hydrolase (GH) families GH27 and GH43. Examples of proteins which contain CBM35s belonging to this family includes the CBM35 of an exo-beta-1,3-galactanase from Phanerochaete chrysosporium 9 (Pc1,3Gal43A) which is appended to a GH43 domain, and the CBM35 domain of two bifunctional proteins with beta-L-arabinopyranosidase/alpha-D-galactopyranosidase activities from Fusarium oxysporum 12S, Foap1 and Foap2 (Fo/AP1 and Fo/AP2), that are appended to GH27 domains. CBM35s are unique in that they display conserved specificity through extensive sequence similarity but divergent function through their appended catalytic modules. They are known to bind alpha-D-galactose (Gal), mannan (Man), xylan, glucuronic acid (GlcA), a beta-polymer of mannose, and possibly glucans, forming four subfamilies based on general ligand specificities (galacto, urono, manno, and gluco configurations). Some CBM35s bind their ligands in a calcium-dependent manner. In contrast to most CBMs that are generally rigid proteins, CBM35 undergoes significant conformational change upon ligand binding. GH43 includes beta-xylosidases and beta-xylanases, using aryl-glycosides as substrates, while family GH27 includes alpha-galactosidases, alpha-N-acetylgalactosaminidases, and isomaltodextranases.