Characterization of Family 3 Carbohydrate-binding Module from Clostridium josui

Binding properties of the family 3 carbohydratebinding module which is one of the modules of a scaffold protein of the cellulosomes from Clostridium josui (CjCBM3) was evaluated. Although it is classified to a type of binding to surface of crystalline cellulose, it bound to celluloses which have broad amorphous regions and to soluble xyloglucan. Furthermore it is showed CjCBM3 bound to them though its flat binding site same as it interacts with crystalline surface. This CBM possesses a wider binding surface which includes more hydrophilic residues than other CBMs which are also categorized as crystalline surface binding type. It is revealed that polar hydrophilic residues in the binding site are important to bind to xyloglucan. Additionally it implied they interact with xyloglucan side chains