In-silico analysis of loop residues of the receptor binding domain of bacillus thuringiensis cry2ac11 toxin

Genetic engineering of bacillus thuringiensis cry proteins has resulted in the synthesis of various novel toxin proteins with enhanced insecticidal activity and broader specificity spectrum. toxinreceptor interaction is known to be the most crucial and rate limiting step for toxin activity and specificity determination but still very less information is available regarding the receptors of cry2 proteins and the mechanism of receptor-ligand interactions of bt toxins. in the present work,detailed in-silico studies of the binding epitopes of bacillus thuringiensis cry2ac11 toxin are done. to get the knowledge about the binding characteristics of each single residue in the receptor binding region,various bioinformatics tools have been employed and protein modeling,sequence and structural homology analysis,alanine scanning and protein docking studies were done. also the binding interactions of individual residues with different lepidopteran and dipteran receptors have been predicted. the collective knowledge of cry toxin interactions with its potential receptors will lead to a more critical understanding of the structural basis for receptor binding and specificity determination. this study will serve as a starting point for designing mutagenesis strategies aimed to improve the insecticidal activity of cry proteins.