Bacillus thuringiensis produces insecticidal protein called:
During late sporulation, Bacillus thuringiensis forms intracellular parasporal crystals alongside spores. Protein components are protoxins referred to as delta-endotoxins because they act within insect midgut after ingestion and are endotoxin-like in crystal formation. Sequence classification divides them into Cry families sharing three-domain structure: domain I seven antiparallel alpha-helices responsible for pore formation, domain II beta prism determining receptor specificity, domain III beta sandwich stabilizing structure. Crystal solubilization requires alkaline pH above 9.5 common in le
Ref: Schnepf Microbiol Mol Biol Rev 1998 delta-endotoxin; NCBI NBK24601 Cry proteins; Crickmore Microbiol Rev 1998 nomenclature; https://www.ncbi.nlm.nih.gov/books/NBK24601/
