Deletion by in vivo recombination shows that the 28-kilodalton cytolytic polypeptide from Bacillus thuringiensis subsp. israelensis is not essential for mosquitocidal activity
Autor(es): Delecluse, A; Charles, JF; Klier, A; Rapoport, G
Resumo: The cytA gene encoding the 28-kDa polypeptide of Bacillus thuringiensis subsp. israelensis crystals was disrupted in the 72-MDa resident plasmid by in vivo recombination, thus indicating that homologous recombination occurs in B. thuringiensis. The absence of the 28-kDa protein in B. thuringiensis did not affect the crystallization of the other toxic components of the parasporal body (68-, 125-, and 135-kDa polypeptides). The absence of the 28-kDa protein abolished the hemolytic activity of B. thuringiensis subsp. israelensis crystals. However, the mosquitocidal activity of the 28-kDa protein-free crystals did not differ significantly from that of the wild-type crystals when tested on Aedes aegypti and Culex pipiens larvae. The 28-kDa protein contributed slightly to the toxicity to Anopheles stephensi larvae. This indicates that the 28-kDa protein is not essential for mosquitocidal activity, at least against the three species tested.
Palavras-Chave: Delta - Endotoxin gene; Escherichia - Coli; Nucleotide - Sequence; Crystal proteins; Plasmid DNA; Expression; Subtilis; Cloning; Toxin; Amplification
Imprenta: Journal of Bacteriology, v. 173, n. 11, p. 3374-3381, 1991
Identificador do objeto digital: 10.1128/jb.173.11.3374-3381
Descritores: Aedes aegypti - DNA
Data de publicação: 1991
