Abstract
Bacillus thuringiensis insecticidal protein, Cry1Aa toxin, binds to a specific receptor in insect midguts and has insecticidal activity. Therefore, the structure of the receptor molecule is probably a key factor in determining the binding affinity of the toxin and insect susceptibility. The cDNA fragment (PX frg1) encoding the Cry1Aa toxin-binding region of an aminopeptidase N (APN) or an APN family protein from diamondback moth, Plutella xylostella midgut was cloned and sequenced. A comparison between the deduced amino acid sequence of PX frg1 and other insect APN sequences shows that Cry1Aa toxin binds to a highly conserved region of APN family protein. In this paper, we propose a model to explain the mechanism that causes B. thuringiensis evolutionary success and differing insect susceptibility to Cry1Aa toxin.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Aminopeptidases / chemistry
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Aminopeptidases / genetics
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Aminopeptidases / metabolism*
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Animals
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Bacillus thuringiensis / metabolism*
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Bacillus thuringiensis Toxins
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Bacterial Proteins / metabolism*
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Bacterial Toxins*
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Cloning, Molecular
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DNA, Complementary / biosynthesis
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DNA, Complementary / chemistry
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Endotoxins / metabolism*
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Hemolysin Proteins / metabolism*
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Immunoblotting
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Insect Proteins*
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Insecta / microbiology*
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Insecticides / metabolism*
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Larva
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Malpighian Tubules / metabolism
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Molecular Sequence Data
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Sequence Alignment
Substances
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Bacillus thuringiensis Toxins
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Bacterial Proteins
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Bacterial Toxins
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DNA, Complementary
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Endotoxins
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Hemolysin Proteins
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Insect Proteins
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Insecticides
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insecticidal crystal protein, Bacillus Thuringiensis
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Aminopeptidases