9VEK

Structural basis for the assembly and translocation of the Vip1-Vip2 insecticidal binary toxin from Bacillus thuringiensis

Summary for 9VEK

• Entry DOI: 10.2210/pdb9vek/pdb
• EMDB information: 65010
• Descriptor: Vip1, CALCIUM ION (2 entities in total)
• Functional Keywords: binary toxin, biopesticide, toxin
• Biological source: Bacillus thuringiensis
• Total number of polymer chains: 7
• Total formula weight: 509422.98

Authors

Chen, P.,Zhao, T. (deposition date: 2025-06-09, release date: 2026-04-15)

Primary citation

Zhao, T.,Wang, Z.,Ren, J.,Han, X.,Li, L.,Liu, Z.,Zhang, J.,Chen, P.
Structural basis for the assembly and translocation of the Vip1-Vip2 insecticidal toxin from Bacillus thuringiensis.
Nat Commun, 2026

PubMed Abstract: Insecticidal toxins from Bacillus thuringiensis (Bt) have been extensively and successfully used in genetically engineered crops for decades but continue to face challenges from the adaptive resistance in the insect population. The Bt binary toxin Vip1Ad1(Vip1) and Vip2Ag1(Vip2), a promising next-generation candidate gene combination for transgenic crops, have demonstrated high efficacy against the destructive coleopteran pest white grubs, however, their mode of action remains largely elusive. In this study, we report cryo-EM structures of the heptameric Vip1-pore and Vip2-bound Vip1-pore complex, capturing a series of putative assembly-related intermediates that suggest a binary toxin assembly and translocation pathway. Together with structure-guided mutagenesis, these data provide insights into a sequential assembly of binary complex and a sequence-independent translocation mechanism. Proof-of-principle experiments showed successful delivery of a desired protein cargo into host cells based on the mini-Vip2-Vip1 pore system, paving the way for developing much needed extracellular pesticidal protein delivery platforms. These findings not only clarify the assembly and translocation mechanism of the binary insecticidal toxin pair but also offer an excellent alternative model to investigate human-pathogenic pore-forming toxins because of its similarity and biosafety.

PubMed: 41912579
DOI: 10.1038/s41467-026-71211-7

Experimental method

ELECTRON MICROSCOPY (3.31 Å)