Cloning and sequencing of a chitinase gene from Vibrio alginolyticus H-8

A gene from Vibrio alginolyticus H-8, encoding chitinase, designated as chi tinase B, was cloned by the shot-gun method using pUC118 and sequenced. The open reading frame consisted of 846 amino acids including a signal peptide . The molecular mass of the enzyme estimated based on the amino acid sequen ce data was 90 kDa. The N-terminal amino acid sequence of the enzyme was di fferent from that of chitinase C1 which we had previously reported. This cl oned chitinase B was considered one out of four chitinases (A, B, D, and E) which had been newly isolated from the culture broth and cell extract of E alginolyticus H-8. The gene contained a chitin-binding domain and typical conserved regions of chitinases reported previously. The deduced amino acid sequence of the cloned chitinase B showed high sequence homology with the chitinase from V. parahaemolyticus (84% identity) and the chitinase from V. anguillarum (76.6%), but low sequence homology with the chitinase from V. harveyi (24.4%), and the chitodextrinase from V, furnissii (23.9%). Chitina se E found in cell extract is considered an Intracellular chitinase which i s different from chitodextrinases.