Interactions between family 3 carbohydrate binding modules (CBMs) and cellulosomal linker peptides.

Family 3 carbohydrate-binding modules (CBM3s) are among the most distinctive, diverse, and robust. CBM3s, which are numerous components of both free cellulases and cellulosomes, bind tightly to crystalline cellulose, and thus play a key role in cellulose degradation through their substrate targeting capacity. In addition to the accepted cellulose binding surface of the CBM3 molecule, a second type of conserved face (the "shallow groove") is retained on the opposite side of the molecule in all CBM3 subfamilies, irrespective of the loss or modification of the cellulose-binding function.