Structural journey of an insecticidal pore-forming protein targeting western corn rootworm

Marini, G.; Poland, B.; Leininger, C.; Lukoyanova, N.; Spielbauer, D.; Barry, J.; Altier, D.; Lum, A.; Scolaro, E.; Perez Ortega, C.; Yalpani, N.; Sandahl, G.; Mabry, T.; Klever, J.; Nowatzki, T.; Zhao, J.-Z.; Sethi, A.; Kassa, A.; Crane, V.; Lu, A.; Nelson, M.; Eswar, N.; Topf, M.; Saibil, H.

doi:10.1101/2022.10.12.511876

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bioRxiv · 10.1101/2022.10.12.511876

Structural journey of an insecticidal pore-forming protein targeting western corn rootworm

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Abstract

Broad adoption of transgenic crops has revolutionized agriculture. However, resistance to insecticidal proteins by agricultural pests poses a continuous challenge to maintaining crop productivity and new proteins are urgently needed to replace existing transgenic traits. We identified an insecticidal membrane attack complex/perforin (MACPF) protein, Mpf2Ba1, with strong activity against western corn rootworm larvae and a novel site of action. By integrating X-ray crystallography, cryo-EM, and modelling, we determined monomeric, pre-pore and pore structures, revealing changes between structural states at atomic resolution. We discovered a monomer inhibition mechanism, a molecular "switch" associated with pre-pore activation/oligomerization upon gut fluid incubation and solved the highest resolution MACPF pore structure to-date. Our findings provide a mechanistic basis for Mpf2Ba1 effectiveness as an insecticidal protein with potential for biotechnology development. One-Sentence SummaryThe molecular mechanism of an insecticidal protein is revealed through 3D structures of the three main pore formation states

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Marini, G., Poland, B., Leininger, C., Lukoyanova, N., Spielbauer, D., Barry, J., Altier, D., Lum, A., Scolaro, E., Perez Ortega, C., Yalpani, N., Sandahl, G., Mabry, T., Klever, J., Nowatzki, T., Zhao, J.-Z., Sethi, A., Kassa, A., Crane, V., Lu, A., Nelson, M., Eswar, N., Topf, M., Saibil, H.. 2022-10-12. Structural journey of an insecticidal pore-forming protein targeting western corn rootworm. https://doi.org/10.1101/2022.10.12.511876

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