在Photorhabdus luminescens中,类似注射器的注射机制会产生毒素
Christos Gatsogiannis1, Alexander E Lang, Dominic Meusch
1Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.
Nature
|March 22, 2013
概括
Photorhabdus luminescens使用ABC类型的毒素复合物来杀死昆虫. 研究人员确定了关键毒素成分的结构,揭示了将致命蛋白质送入宿主细胞的新型机制.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- Photorhabdus luminescens是一种与线虫共生的昆虫病原体.
- 它利用大型三方ABC型毒素复合体 (Tcs) 进行毒性.
- TcC蛋白质是活性成分,作为ADP-ribosyltransferases起作用.
研究的目的:
- 阐明TcA和TcB通过TcC转移到宿主细胞的机制.
- 为了确定Tc复合体TcdA1组件的结构.
- 了解pH在Tc复杂膜插入中的作用.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 确定了TcdA1在预孔和孔隙状态中的结构.
- 在不同状态下的TcdA1之间进行了结构性比较,并与其他Tc组件进行了复合.
- 研究了pH对膜插入的影响.
主要成果:
- TcdA1形成了一个带有狭窄α螺旋通道的五角形跨膜孔.
- 膜插入是由低和高的pH触发的.
- 形状变化表明蛋白质转位的类似注射器的机制.
结论:
- 这项研究揭示了ABC型毒素跨膜转移的新型机制.
- 这为P. luminescens. 的宿主-病原体相互作用提供了洞察力.
- 这些发现支持开发新型生物农药.
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