Molecular engineering of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040: structural determinants for the reaction product size and reactivity

Bacillus circulans T-3040 cycloisomaltooligosaccharide glucanotransferase (BcCITase) mainly produces cycloisomaltooctaose. By structure-based mutagenesis of a carbohydrate-binding module family 35 (BcCBM35) and catalytic domain, the product specificity was modified and catalytic activity was improved, which enabled us to obtain a greater yield of cycloisomaltodecaose.