一个Tad分泌系统的组装机制分泌在飞行员复合体中
Matteo Tassinari1,2, Marta Rudzite3, Alain Filloux3,4
1Department of Infectious Disease, Imperial College, London, SW7 2AZ, UK.
Nature communications
|September 13, 2023
概括
细菌的紧固粘附分泌系统 (TadSS) 使用RcpA和TadD形成一个密封道,这对于柱子组装至关重要. 这项研究揭示了它们独特的结合机制和结构组装.
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:
- 细菌紧密粘附分泌系统 (TadSS) 对于柱子组装至关重要,驱动细菌粘附和生物膜形成.
- 塔德SS的精确结构和机制,特别是它的外膜分泌物和飞行员招募,仍然在很大程度上没有特征.
研究的目的:
- 研究RcpA和TadD脂蛋白在*Pseudomonas aeruginosa*中的TadSS分泌道组装中的作用.
- 阐明RcpA和TadD之间的结构基础和相互作用机制.
主要方法:
- 使用光显微镜可视化了RcpA和TadD在P. aeruginosa和Escherichia coli中的局部.
- 使用冷电子显微镜 (cryo-EM) 来确定RcpA-TadD复合体的高分辨率结构.
- 进行了生物化学测试,以确认RcpA和TadD之间的相互作用.
主要成果:
- 观察到RcpA和TadD的局部化,这表明TadSS中的功能关联.
- 低温电磁波显示,RcpA和TadD组装成一个表现出C13和C14对称性的秘密道.
- 尽管TadD具有低序列同样性,但它与PilF类型4的飞行系统飞行员具有相似的折叠.
- 确定RcpA的C端四个残留物对于结合TadD至关重要,这是分泌形成的关键步骤.
结论:
- RcpA和TadD形成了一种对TadSS功能至关重要的新型分泌通道.
- 这种RcpA-TadD相互作用机制与之前描述的分泌素-飞行素配对有所区别,为细菌分泌系统提供了新的见解.
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