RRC ID |
3358
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著者 |
Daimon T, Katsuma S, Iwanaga M, Kang W, Shimada T.
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タイトル |
The BmChi-h gene, a bacterial-type chitinase gene of Bombyx mori, encodes a functional exochitinase that plays a role in the chitin degradation during the molting process.
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ジャーナル |
Insect Biochem Mol Biol
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Abstract |
The silkworm, Bombyx mori, has been recently demonstrated to contain a bacterial-type chitinase gene (BmChi-h) in addition to a well-characterized endochitinase gene (BmChitinase). The deduced amino acid sequence of BmChi-h showed extensive structural similarities with chitinases from bacteria such as Serratia marcescens chiA and baculoviruses (v-CHIA). Bacterial-type chitinase genes have not been found from any eukaryotes and viruses except for lepidopteran insects and lepidopteran baculoviruses. Thus, it was suggested that BmChi-h may be derived from a bacterial or baculovirus chitinase gene via horizontal gene transfer. In this report, we investigated the biological function of BmChi-h. Our enzymological study indicated that a chitinase encoded by BmChi-h has exo-type substrate preference, which is the same as S. marcescens chiA and v-CHIA, and different from BmChitinase, which has endo-type substrate preference. An immunohistochemical study revealed that BmChi-h localizes in the chitin-containing tissues during the molting stages, indicating that it plays a role in chitin degradation during molting. These results suggest that BmChi-h (exochitinase) and BmChitinase (endochitinase) may catalyze a native chitin by a concerted mechanism. Cloning and comparison of BmChi-h orthologues revealed that bacterial-type chitinase genes are highly conserved among lepidopteran insects, suggesting that the utilization of a bacterial-type chitinase during the molting process may be a general feature of lepidopteran insects.
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巻・号 |
35(10)
|
ページ |
1112-23
|
公開日 |
2005-10-1
|
DOI |
10.1016/j.ibmb.2005.05.005
|
PII |
S0965-1748(05)00120-7
|
PMID |
16102417
|
MeSH |
Amino Acid Sequence
Amino Acid Substitution
Animals
Base Sequence
Bombyx / enzymology
Bombyx / genetics*
Bombyx / growth & development
Chitin / metabolism*
Chitinases / genetics*
Conserved Sequence
DNA Primers
Hydrogen-Ion Concentration
Molecular Sequence Data
Molting / physiology*
Mutagenesis, Site-Directed
Polymerase Chain Reaction
Sequence Alignment
Sequence Homology, Amino Acid
|
IF |
3.827
|
引用数 |
41
|
WOS 分野
|
ENTOMOLOGY
BIOCHEMISTRY & MOLECULAR BIOLOGY
|
リソース情報 |
カイコ |
Samia cynthia ?
Antheraea pernyi |