Exchange of domain I from Bacillus thuringiensis Cry1 Toxins Influences protoxin stability and crystal formation.
Influence of domain I exchange on the stability and production of Bacillus thuringiensis Cry1 protoxins as well as on the shape of inclusion and toxicity to Spodoptera exigua and Plutella xylostella larvae was investigated. Chimeric genes were prepared by exchanging the regions coding for domain I between Cry1Aa, Cry1Ab, Cry1Ac, Cry1C, and Cry1E. The AcCC chimera accumulated into bipyramidal inclusion bodies, whereas CEE produced round-shaped inclusion bodies, and ECC and AaEE protoxins produced small granules. AbEE and EAaAa did not produce any inclusion body and were visualized by immunodetection only. AcCC, CEE, ECC, and AaEE were stable to trypsin, whereas AbEE and EAaAa were not. Bioassays showed that the chimeras were not toxic in vivo. However, S. exigua larvae fed with the activated AcCC toxin displayed a lower growth rate.
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CIRAD, TA 40/PS1, Boulevard de la Lironde, 34398 Montpellier Cedex 5, France.
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D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D006460:Hemolysin Proteins; D002479:Inclusion Bodies / Q000382:microbiology; D009036:Moths / Q000187:drug effects; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000633:toxicity; D018411:Spodoptera / Q000187:drug effects; D014169:Transformation, Bacterial / Q000235:genetics
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis