来自Photorhabdus akhurstii亚种的PirA和PirB毒素的晶体结构. akhurstii K-1 的时间
Arpit Prashar1, Omkar U Kinkar2, Ashwani Kumar3
1Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, 400085, Maharashtra, India.
Insect biochemistry and molecular biology
|October 1, 2023
概括
来自Photorhabdus的PirAB二元毒素对昆虫害虫有毒. 它的晶体结构与Bacillus thuringiensis Cry毒素有相似之处,这表明有孔形成机制. 肠杆菌重复性基因间共识 (ERIC) 序列对于其体内毒性至关重要.
科学领域:
- 结构生物学是结构生物学.
- 昆虫毒理学 昆虫毒理学
- 细菌毒素是一种毒素.
背景情况:
- 来自Photorhabdus的PirAB二元毒素是对二虫和虫虫害的有力剂.
- 了解PirAB的三维结构和毒性机制对于开发新型生物农药至关重要.
研究的目的:
- 确定来自Photorhabdus akhurstii亚种的PirA和PirB蛋白质的晶体结构. 在 akhurstii K-1.
- 阐明PirAB毒性的结构基础及其潜在的作用机制.
主要方法:
- 使用X射线晶体学,分别以1.6和2.1 Å分辨率确定PirA和PirB蛋白的3D结构.
- 与已知的杀虫剂蛋白质进行结构比较,例如Bacillus thuringiensis Cry毒素.
- 对Galleria mellonella幼虫进行了毒性测试,使用纯化的PirA和PirB蛋白进行了测试,无论是单独的还是复合的.
主要成果:
- PirA表现出一种果卷拓,而PirB由N端螺旋和C端β链域组成.
- PirA和PirB与Bacillus thuringiensisCry δ-endotoxins的域具有结构相似性,这表明Cry蛋白毒性机制的潜在模仿,包括毛孔形成.
- 独立净化PirA和PirB没有毒性;然而,PirA-PirB复合体表达的Enterobacterial Repetitive Intergenic Consensus (ERIC) 序列在Galleria mellonella中显示出显著的毒性 (LD50 = 1.62μg/幼虫).
- 肠杆菌重复性基因间共识 (ERIC) 序列似乎是实现PirAB复合体在体内有毒构成的关键.
结论:
- PirA和PirB的晶体结构提供了对它们的架构和潜在功能的洞察.
- 结构上与Cry毒素的相似性表明PirAB可能通过类似的毛孔形成机制起作用.
- 肠杆菌重复性基因间共识 (ERIC) 序列在PirAB二元毒素的体内激活和毒性中发挥着关键作用.
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