Composite

Part:BBa_K5066011

Designed by: Abner Tseng   Group: iGEM24_GEMS-Taiwan   (2024-09-27)


Xpp81Aa-Cyt2Ba

Description

Insecticide resistance is becoming increasingly problematic and prominent in many Southeast Asian countries, areas where dengue fever is prevalent. The combination of Bt toxins and scorpion toxins is a promising strategy providing a potential layer of protection against insecticide resistance. The ribosome binding site(RBS) is a sequence of nucleotides before the start codon of an mRNA transcript and functions to recruit ribosomes for the translation of proteins. The his-tag, 6X His, is a commonly used purification tag that contains 6 consecutive histidine residues. The His-tag can be stained with His-tag antibodies after translation, labelling the target recombinant protein. It is typically placed on either the N or C terminus of a protein.


Usage and Biology

Xpp81Aa1 is a Bt toxin that is used as an insecticide as it can target specific insects without causing harm to other species. There are a wide variety of strains derived from a selection of Bt bacteria and each has similar effects but targets different species of insects. There are three main categories of the Bt toxin: Cry, Cyt, and Vip; there are also the Xpp, which were reclassified from Cry. Cyt2ba is a toxin that binds to membrane receptors and increases membrane permeability. In Aedes mosquitoes, the toxin binds to the midgut of the mosquito larvae. Due to its crystalline structure, the toxin alters the cell membrane’s permeability which is crucial for cellular transport and activities, ultimately leading to the death of the larvae as a result of malnutrition and damage to the cell membrane.


Table 2. The mortality rate of Aedes albopictus larvae exposed to various combinations of biolarvicidal toxins.

Our results indicated that the combination of two or three biolarvicidal toxins achieved a maximum mortality rate of only 33.33%. The limited effectiveness observed in this study highlights the need for further research to optimize for more effective toxin combinations and formulations.

Sequence and Features


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal EcoRI site found at 1595
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal EcoRI site found at 1595
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal EcoRI site found at 1595
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal EcoRI site found at 1595
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal EcoRI site found at 1595
  • 1000
    COMPATIBLE WITH RFC[1000]


Reference

Wu, J., Wei, L., He, J., Fu, K., Li, X., Jia, L., Wang, R., & Zhang, W. (2021). Characterization of a novel Bacillus thuringiensis toxin active against Aedes aegypti larvae. Acta tropica, 223, 106088. https://doi.org/10.1016/j.actatropica.2021.106088

Yu-Mei Xiong, Min-Hua Ling, Zheng-Dao Lan, Da-Cheng Wang, Cheng-Wu Chi,The cDNA sequence of an excitatory insect selective neurotoxin from the scorpion Buthus martensi Karsch,Toxicon, Volume 37, Issue 2, 1999, Pages 335-341, ISSN 0041-0101, https://doi.org/10.1016/S0041-0101(98)00176-7.

Deng, S. Q., Deng, M. Z., Chen, J. T., Zheng, L. L., & Peng, H. J. (2017). Nan fang yi ke da xue xue bao = Journal of Southern Medical University, 37(6), 750–754. https://doi.org/10.3969/j.issn.1673-4254.2017.06.06

Bravo, A., Likitvivatanavong, S., Gill, S. S., & Soberón, M. (2011). Bacillus thuringiensis: A story of a successful bioinsecticide. Insect biochemistry and molecular biology, 41(7), 423–431. https://doi.org/10.1016/j.ibmb.2011.02.006

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