Open AccessIsolation and characterization of the 54‐kDa and 22‐kDa chitinase genes of Serratia marcescens KCTC2172 1
Author(s) -
Gal Sang Wan,
Choi Ji Young,
Kim Cha Young,
Hwa Cheong Yong,
Choi Young Ju,
Bahk Jeong Dong,
Lee Sang Yeol,
Cho Moo Je
Publication year - 1997
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1997.tb12570.x
Subject(s) - chitinase , serratia marcescens , open reading frame , biology , nucleic acid sequence , biochemistry , microbiology and biotechnology , chitin , peptide sequence , escherichia coli , gene , chitosan
A DNA fragment (pCHI5422) containing two genes encoding a 54‐kDa and a 22‐kDa chitinase was isolated from a cosmid DNA library of Serratia marcescens KCTC2172. The complete nucleotide sequence of pCHI5422 consisting of 4581 bp was determined. The nucleotide sequence of the 22‐kDa chitinase consists of 681 bp of open reading frame encoding 227 amino acids and is located 1422 bp downstream of the translation termination codon of the 54‐kDa chitinase sequence. The 54‐kDa chitinase gene consisted of 1497 bp in a single open reading frame encoding 499 amino acids. The genes encoding the 54‐kDa and 22‐kDa chitinase were separately subcloned in Escherichia coli and the individual chitinases were expressed and purified from the culture broth using chitin affinity chromatography. When chitohexaose was used as substrate, the major product of the enzymatic reaction of both the 54‐kDa and 22‐kDa chitinases was a (GlcNAc) 2 dimer with a minor amount of monomer. The specific activity of the 54‐kDa and 22‐kDa chitinases were 300 μM (min) −1 mg −1 and 17 μM (min) −1 mg −1 on the natural swollen chitin, respectively.