Analysis of binding of the family 2a carbohydrate-binding module from Cellulomonas fimi xylanase 10A to cellulose: specificity and identification of functionally important amino acid residues.

摘要: The family 2a carbohydrate-binding module (CBM2a) of xylanase 10A from Cellulomonas fimi binds to the crystalline regions cellulose. It does not share binding sites with N-terminal 4 (CBM4-1) cellulase 9B C.fimi, a that strictly soluble sugars and amorphous CBM2a matrices is mediated by several residues on face, including three prominent, solvent-exposed tryptophan residues. Binding cellulose was analyzed making series conservative (phenylalanine tyrosine) non-conservative substitutions (alanine) each (W17, W54 W72). Other face hydrogen bonding potential were substituted alanine. Each plays different role in binding; essential at position 54, tyrosine or 17 any aromatic residue 72. exception N15, are determinants affinity. Given specificity CBM2a, structure dynamic nature we propose model for interaction between polypeptide surface.