Delineation of the minimal portion of the Bacillus sphaericus 1593M toxin required for the expression of larvicidal activity.
The two genes of Bacillus sphaericus 1953M coding for the 51.4-kDa and 41.9-kDa proteins are both required for the expression of the active larvicidal toxin in Escherichia coli. The minimal size of the active peptide of the 41.9-kDa toxin was defined by in vitro deletion analysis of the gene and found to consist of 338 amino acids (38.3 kDa). N-terminal deletions past the Ile18 residue and C-terminal deletions past the His352 residue result in the loss of toxic activity and rapid degradation of such modified toxins by host proteases. The minimal active 38.3-kDa peptide produced in E. coli seems to mimick the stable processed form of the toxin found in larval midguts. However, it still requires the action of the synergistic 51.4-kDa protein for the larvicidal activity.
Sebo
P
P
Laboratoire d'Enzymologie, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
Bennardo
T
T
de la Torre
F
F
Szulmajster
J
J
D000595:Amino Acid Sequence; D001407:Bacillus / Q000472:pathogenicity*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology / Q000633:toxicity*; D015153:Blotting, Western; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011994:Recombinant Proteins; D015183:Restriction Mapping; D013329:Structure-Activity Relationship
D001427:Bacterial Toxins; D011994:Recombinant Proteins; C046134:binB protein, Bacillus sphaericus