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US 6,033,874 AGranted
CRY1C polypeptides having improved toxicity to lepidopteran insects
AssigneeEcogen Inc.
InventorsJames A. Baum, Amy Jelen Gilmer, Ann-Marie Light Mettus
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AssigneeEcogen Inc.
InventorsJames A. Baum, Amy Jelen Gilmer, Ann-Marie Light Mettus
Estimating the term…
Disclosed are novel synthetically-modified B. thuringiensis nucleic acid segments encoding .delta.-endotoxins having insecticidal activity against lepidopteran insects. Also disclosed are synthetic crystal proteins encoded by these novel nucleic acid sequences. Methods of making and using these genes and proteins are disclosed as well as methods for the recombinant expression, and transformation of suitable host cells. Transformed host cells and transgenic plants expressing the modified endotoxin are also aspects of the invention. Also disclosed are methods for modifying, altering, and mutagenizing specific loop regions between the .alpha. helices in domain 1 of these crystal proteins, including Cry1C, to produce genetically-engineered recombinant cry* genes, and the proteins they encode which have improved insecticidal activity. In preferred embodiments, novel Cry1C* amino acid segments and the modified cry1C* nucleic acid sequences which encode them are disclosed.
An isolated Bacillus thuringienis Cry1C .delta.-endotoxin polypeptide comprising one or more amino acid mutations in the loop region between .alpha. helices 6 and 7 of domain 1, wherein the polypeptide has improved insecticidal activity against Lepidopteran insects relative to a native Cry1.delta.-endotoxin polypeptide.
A composition comprising a Bacillus thuringienis Cry1C .delta.-endotoxin polypeptide, wherein the polypeptide comprises one or more amino acid mutations in the loop region between .alpha. helices 6 and 7 of domain 1, and the polypeptide has improved insecticidal activity against Lepidopteran insects relative to a native Cry1C .delta.-endotoxin polypeptide.
A method of preparing a Bacillus thuringienis Cry1C .delta.-endotoxin polypeptide, comprising the steps of:
An isolated nucleic acid segment encoding a Bacillus thuringienis Cry1C .delta.-endotoxin polypeptide, wherein the polypeptide comprises one or more amino acid mutations in the loop region between .alpha. helices 6 and 7 of domain 1, and the polypeptide has improved insecticidal activity against Lepidopteran insects relative to a native Cry1C .delta.-endotoxin polypeptide.
A nucleic acid vector comprising operably linked in the 5' to 3' direction:
A host cell comprising operably linked in the 5' to 3' direction:
A transgenic plant comprising operably linked in the 5' to 3' direction:
A method of controlling Lepidopteran insects comprising contacting said insects with an insecticidally-effective amount of a Bacillus thuringienis Cry1C .delta.-endotoxin polypeptide, wherein:
Dependencies are inferred from the claim text.