Cloning and sequencing of two genes encoding chitinases A and B from Bacillus cereus CH

Two genes encoding chitinases A and B (chiA and chiB) from Bacillus cereus CH were cloned into Escherichia coli XL1-Blue MRF' by using pBluescript II SK+, and their nucleotide sequences were determined. Open reading frames of the chiA and chiB genes encoded distinct polypeptide chains consisting of 360 and 674 amino acid residues, respectively, with calculated molecular si zes of 39 470 and 74 261 Da, respectively. Comparison of the deduced amino acid sequences with those of other bacterial chitinases revealed that chiti nase A consisted of a catalytic domain, while chitinase B consisted of thre e functional domains, a catalytic domain, a fibronectin type III-like domai n, and a cellulose-binding domain. The primary structures of these two prot eins were not similar to each other.