[Cloning and sequencing of chitinase gene from Bacillus thuringiensis subsp israelensis].
Chitin, a linear homopolymer of N-acetyl-D-glucosamine, is a common constituent of fungal cell walls, exoskeletons of insects, and shells of invertebrates. Thus, chitinase, a chitin hydrolytic enzyme, has become of interest for potential use as biopesticides for controlling insect pests. Using a pair of specific primers, chitinase gene (ichi) was amplified by touchdown PCR from Bacillus thuringiensis subsp israelensis chromosomal DNA, and then subcloned into pGEM-T easy vector. ichi sequence (GenBank Accession Number: AF526379) with a length of 2570 bp included an open reading frame (ORF) of 2067 bp, which contained 688 amino acids with Mr = 75.79 kDa and pI = 5.90. The amino acid sequence of ichi gene shows 97.24%, 97.18%, 97.63% and 63.07% identity to that of Bacillus cereus strain 28-9 chitinase CW, Bacillus cereus CH chitinase B, Bt subsp Mexican chitinase, and Bt subsp pakistani chitinase A71, respectively. It was demonstrated that Ichi contains a signal peptide (46 amino acid residues) and three functional domains: an N-terminal catalytic domain (105 amino acid residues), a fibronectin type III like domain (74 amino acid residues), and a C-terminal chitin-binding domain (40 amino acid residues).
Zhong
Wan-Fang
WF
Biotechnological Breeding Center, Sichuan Academy of Agricultural Science, Chengdu 610066, China.
Jiang
Li-Hua
LH
Yan
Wen-Zhao
WZ
Cai
Ping-Zhong
PZ
Zhang
Zhi-Xiong
ZX
Pei
Yan
Y
D000595:Amino Acid Sequence; D001413:Bacillus thuringiensis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D002688:Chitinases / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D004269:DNA, Bacterial; D002688:Chitinases