Sequence of an operon containing a novel δ-endotoxin gene from Bacillus thuringiensis |
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Authors: | D Wu XL Cao YY Bai AI Aronson |
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Institution: | Department of Biological Sciences, Purdue University, West Lafayette, IN 47907. |
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Abstract: | An insect larval toxin designated CryII is produced by several subspecies of Bacillus thuringiensis and differs from the other major delta-endotoxins in these bacteria in its size, toxicity profile and presence as part of an operon with three open reading frames (ORF). Such an operon from a novel B. thuringiensis isolate has been cloned and differs from one previously characterized in the following ways: (a) the size and number of amino acid repeats in one of the ORFs; (b) the smaller size of the CryII protoxin and the presence of a unique 110-kDa CryII-related antigen; and (c) high larvicidal activity for a particular Lepidopteran but low activity for a Dipteran. Various subclones of this operon were introduced into a plasmid-free B. thuringiensis strain and only the cryII gene was found to be necessary for protoxin accumulation. |
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Keywords: | CryII endotoxin Lepidopteran active Amino acid repeats |
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