Fig. 7: The proposed model Cry78Aa uses to kill rice planthoppers. | Communications Biology

Fig. 7: The proposed model Cry78Aa uses to kill rice planthoppers.

From: The crystal structure of Cry78Aa from Bacillus thuringiensis provides insights into its insecticidal activity

Fig. 7

According to the structural and biochemical results in this study, we proposed that the Cry78Aa may kill L. striatellus nymphs by the following steps: I. The NTD of Cry78Aa recognizes carbohydrates such as galactose, lactose or GalNAc on the cell membrane surface receptor. II. The NTD of Cry78Aa binds to receptors (such as Gal-linked glycolipid or glycoprotein) on the membrane under the guidance of carbohydrates. III. With the help of receptors, the local concentration increase of monomers will promote oligomerization, and the pore-forming domains (CTDs) of Cry78Aa assemble to form a giant oligomer. IV. Molecular rearrangement of each protomer inside the Cry78A oligomer, leading to a prepore assembly. V. β-Barrel formation will create a pore in the bilayer, leading to the disruption of membrane homeostasis and ultimately to cell lysis.

Back to article page