Key residues of Bacillus thuringiensis Cry2Ab for oligomerization and pore-formation activity

Abstract As a pore-forming toxin, activation, oligomerization and pore-formation were both required for the mode of action Cry toxins. Previous results revealed that helices α4–α5 Domain I involved in Cry2Ab, however, key residues Cry2Ab aggregation remained ambiguous. In present studies, we built 20 alanine mutants site-directed demonstrated N151A, T152A, F157A, L183A, L185A I188A could reduce assembly 250 kDa oligomers, suggesting these mutation might be essential oligomerization. expected, all variants showed lower insecticidal activity against P. xylostella . Furthermore, found activities also decreased when compared to wild-type Cry2Ab. Taken together, our data identified emphasized was closely related