CLONING AND EXPRESSION OF A NEW CHITINASE FROM PREDATIVE PLANTS DROSERA CAPENSIS
Novel chi19 gene encoding the chitinase, belonging to the 19th glycosyl hydrolase family from the predatory plant Drosera capensis was cloned and expressed in the E. coli bacterial system. The amino acid sequence of the translated enzyme consists of 325 aa divided into four functional parts: N-terminal signal sequence, catalytic and chitin-binding domains that were linked by the -S-P- linker. The chi19 gene was expressed in two forms: with and without a chitin-binding domain. Refolding was carried out and homogeneous soluble forms were obtained for both variants of the enzyme. Chitinases obtained exhibited predominantly speci f c activity towards crystalline chitin, with optimal pH level from 5.0 to 5.5 and the optimum temperature in the range of 52 to 55 °C for both forms of the enzyme. The catalytic activity of the full-sized form of chitinase was 360 U/g with 64% decrease of the catalytic activity for the form with chitin-binding domain removed.