Abstrakt

Structural and functional analysis of domain Ⅲ of cry1ie toxin

Dongmei Feng, Shuyuan Guo

Cry toxins are insecticidal proteins encoded by cry gene in Bacillus thuringiensis. Cry1I gene is silent in Bt, but can be over expressed as Cry1Ie toxin protein in E.coli. Its active fragment, IE648, can bind with insect peritrophic membrane, which is an important barrier that Cry toxin must pass through before binding with midgut epithelium. Research of our team indicated that domain â…¢ of Cry1Ie seems to take a part in the interaction. In this study structural features of domain â…¢ protein has been analyzed, its function was predicted. It has a â-sandwich structure composed of two bundles of antiparallel â sheets, structurally resemble the carbonhydrate binding proteins, may play a role in binding with polysaccharide like chitin of peritrophic membrane.