Cryo-EM structures of an insecticidal Bt toxin reveal its mechanism of action on the membrane

Abstract Insect pests are a major cause of crop losses worldwide, with an estimated economic cost $470 billion annually. Biotechnological tools have been introduced to control such insects without the need for chemical pesticides; instance, development transgenic plants harbouring genes encoding insecticidal proteins. The Vip3 (vegetative protein 3) family proteins from Bacillus thuringiensis convey toxicity species within Lepidoptera, and wide potential applications in commercial agriculture. proposed exert their activity through pore formation, though date there is no mechanistic description how this occurs on membrane. Here we present cryo-EM structures toxin both inactive activated forms conjunction structural functional data toxin–membrane interactions. Together these demonstrate that Vip3Bc1 complex able insert into membranes highly efficient manner, indicating receptor binding likely driver specificity.