InterPro: IPR001178 Delta endotoxin, central domain

This family contains insecticidal toxins produced by Bacillus species of bacteria. During spore formation the bacteria produce crystals of this protein. When an insect ingests these proteins, they are activated by proteolytic cleavage. The N terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. The activated region of the delta toxin is composed of three distinct structural domains: an N-terminal helical bundle domain (IPR005639) involved in membrane insertion and pore formation; a beta-sheet central domain involved in receptor binding; and a C-terminal beta-sandwich domain (IPR005638) that interacts with the N-terminal domain to form a channel [1, 2]. This entry represents the central beta-sheet domain.