ISSN:
1573-0972
Keywords:
Bacillus thuringiensis
;
Cry1Ea4
;
novel protein
;
sequencing
;
toxicity comparison
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract A new cry gene (cry1Ea4) was cloned and sequenced from a Bacillus thuringiensis isolate native to Mexico (LBIT-147). The gene coded for a 133kDa protoxin which had greater than 99% homology with the holotype Cry1Ea1, as only four mismatches were found between the two amino acid sequences. When the Cry1Ea4 toxin was expressed in a crystal-negative strain of B. thuringiensis, bipyramidal crystals were produced. Purified crystals from this recombinant strain and from the holotype (Cry1Ea1) were bioassayed against first instar larvae of the tobacco hornworm. Statistically different mean LC50 values indicated that Cry1Ea4 was more toxic than its holotype. This increase in toxicity may be attributed to the three amino acids which differ from the holotype sequence in the toxic fragment.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008833815965
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