Comparative analysis of the amino acid sequence of the Cry protein of Bacillus thuringiensis codify the toxic protein to insects of the orders Lepidoptera, Diptera and Lepidoptera/ Diptera

Background The use of Bt crystal protein as a natural insecticide, applied directly to crops has been true for many years. Cry genes codifing these proteins are already are being used in transformation plants that become resistant to certain insects. The aim of this study was to compare the amino acid sequences that encode the Cry protein to insects of the orders Lepidoptera, Diptera and Lepidoptera / Diptera. We evaluated 15 sequences that were deposited in the GenBank and using bioinformatics tools to align and compare these sequences that present three domains (I, II, and III). It is assumed that changes in these domain influence the toxicity of the protein and her order. The results presented indicate the presence of specific regions and that may be related to the specificity of protein toxicity.