6owk
Crystal structure of a Bacillus thuringiensis Cry1B.867 tryptic core variant
Structural highlights
FunctionCR1BE_BACTU Promotes colloidosmotic lysis by binding to the midgut epithelial cells of many lepidopteran larvae.CR1KA_BACTM Promotes colloidosmotic lysis by binding to the midgut epithelial cells of insects. Selectively toxic to Artogeia rapae but not active on Plutella xylostella. Publication Abstract from PubMedTwo new modified Bacillus thuringiensis (Bt) proteins, Cry1Da_7 and Cry1B.868, with activity against fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith), were evaluated for their potential to bind new insect receptors compared to proteins currently deployed as plant incorporated protectants (PIP's) in row crops. Results from resistant insect bioassays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors, demonstrate that receptor utilization of the newly modified Cry1Da_7 and Cry1B.868 proteins are distinct from each other and from commercially available Bt proteins such as Cry1F, Cry1A.105, Cry2Ab and Vip3A. Accordingly, these two proteins target different insect proteins in FAW midgut cells and when pyramided together, should provide durability in the field against this economically important pest.IMPORTANCE There is increased concern with the development of resistance to insecticidal proteins currently expressed in crop plants, especially against high resistance-risk pests such as fall armyworm (FAW), Spodoptera frugiperda, a maize pest that already has developed resistance to Bacillus thuringiensis (Bt) proteins such as Cry1F. Lepidopteran-specific proteins that bind new insect receptors will be critical in managing current Cry1F-resistant FAW and delaying future resistance development. Results from resistant insect assays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that target receptors of the Cry1Da_7 and Cry1B.868 proteins are different from each other and from commercially available Bt proteins such as Cry1F, Cry1A.105, Cry2Ab and Vip3A. Therefore, pyramiding these two new proteins in maize will provide durable control of this economically important pest in production agriculture. Novel receptor interaction of Bacillus thuringiensis Cry1Da_7 and Cry1B.868 proteins allow control of resistant fall armyworm, Spodoptera frugiperda (J.E. Smith).,Wang Y, Wang J, Fu X, Nageotte JR, Silverman J, Bretsnyder EC, Chen D, Rydel TJ, Bean GJ, Li KS, Kraft E, Gowda A, Nance A, Moore RG, Pleau MJ, Milligan JS, Anderson HM, Asiimwe P, Evans A, Moar WJ, Martinelli S, Head GP, Haas JA, Baum JA, Yang F, Kerns DL, Jerga A Appl Environ Microbiol. 2019 Jun 7. pii: AEM.00579-19. doi: 10.1128/AEM.00579-19. PMID:31175187[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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