Prediction of three-dimensional structure of Cry1Ab21 toxin from bacillus thuringiensis Bt IS5056

Abstract

Cry1Ab21 is a δ-endotoxin produced by Bacillus thuringiensis Bt IS5056. The toxic spectrum of this protein is reported to span Lepidopteran, Dipteran and nematodes. Here, we predict the theoretical structural model of newly reported Cry1Ab21 toxin by homology modeling on the structure of the Cry1Aa toxin (2.5Å). Cry1Ab21 resembles the Cry1Aa toxin structure by sharing a common 3D structure with three domains along with few structural deviations. The main differences being located in the length of loops, absence of α7b, α9b, β10, β11, β12 and presence of additional β0 component. Some of the components like α10a, α10b, α11a are spatially positioned at different locations. A better understanding of 3D structure will be helpful in the design of efficient biopecticides. © Society for Plant Biochemistry and Biotechnology 2011.