Heterologous expression, purification and biochemical characterization of endochitinase ChiA74 from Bacillus thuringiensis.

ChiA74 is a secreted endochitinase produced by Bacillus thuringiensis. Previously we have partially characterized the physical parameters that affect enzymatic activity of ChiA74 in crude preparations of bacterial secretomes. In the present study, we cloned the chiA74 open reading frame (ORF) lacking the 5' sequence coding for its secretion signal peptide (chiA74Δsp) into a cold shock expression vector (pColdI) for production of the enzyme in Escherichia coli BL21-Rosetta 2.