Delta endotoxin, central domain, subgroup 2 (IPR015214)

Short name: Endotoxin_cen_dom_subgr2

Domain relationships


Many Bacillus species produce crystals of insecticidal toxins during spore formation. 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 [PMID: 7490762, PMID: 11468393].

This entry represents the central beta-sheet domain, which consistins of three four-stranded beta-sheets, each with a Greek key fold, with internal pseudo threefold symmetry. Thus, it acts as a receptor binding beta-prism, binding to insect-specific receptors of gut epithelial cells [PMID: 11377201]. This entry is found almost exclusively in Bacillus thuringiensis.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.