Site-directed mutagenesis and expression of the soluble form of the family IIIa cellulose binding domain from the cellulosomal scaffolding protein of Clostridium cellulovorans

The planar and anchoring residues of the family IIIa cellulose binding domain (CBD) from the cellulosomal scaffolding protein of Clostridium cellulovorans were investigated by site-directed mutagenesis and cellulose binding studies. By fusion with maltose binding protein, the family IIIa recombinant wild-type and mutant CBDs from C. cellulovorans were expressed as soluble forms. Cellulose binding tests of the mutant CBDs indicated that the planar strip residues played a major role in cellulose binding and that the anchoring residues played only a minor role.