Structural changes upon membrane insertion of the insecticidal pore-forming toxins produced by Bacillus thuringiensis

Different Bacillus thuringiensis (Bt) strains produce a broad variety of pore-forming toxins (PFTs) that show toxicity against insects and other invertebrates. Some these insecticidal PFT proteins have been used successfully worldwide to control diverse insect crop pests. There are several studies focused on describing the mechanism action helped improve their performance cope with resistance evolved by different some proteins. However, crucial information is still missing structure pores formed PFTs, such as three-domain crystal (Cry) proteins, which most commercially Bt in biological In recent years, progress has made identification structural changes certain undergo upon membrane insertion. this review, we describe models proposed for insertion Cry toxins. We also review recently published structures vegetative (Vips; e.g. Vip3) toxin complex (Tc) membrane-inserted state. Although PFTs primary sequences, there similarities three-dimensional Vips addition, all described here must major rearrangements pass from soluble form It that, despite differences, producing an extended α-helix, plays fundamental role perforating target membrane, resulting formation pore required activity.