PAAR重复蛋白质可以提高和多样化VI型分泌系统的峰值
Mikhail M Shneider1,2, Sergey A Buth1, Brian T Ho3
1École Polytechnique Fédérale de Lausanne (EPFL), BSP-415, 1015 Lausanne, Switzerland.
Nature
|August 9, 2013
概括
来自PAAR重复超级家族的蛋白质加剧了第六类分泌系统 (T6SS) 的尖端,使细菌细胞能够释放毒素并杀死猎物. 这一发现揭示了T6SS功能在细菌捕食中的新模型.
科学领域:
- 微生物学 微生物学
- 细菌病原体的产生
- 分子生物学分子生物学
背景情况:
- 细菌的VI型分泌系统 (T6SS) 是一个复杂的机器,对格拉姆阴性细菌的生态相互作用至关重要.
- T6SS促进了有毒效应物到 prokaryotic 和 eukaryotic 细胞的传递,使得捕食成为可能.
- T6SS的精确组成和效应器传递机制在很大程度上是未知的.
研究的目的:
- 阐明PAAR蛋白在T6SS中的结构性作用.
- 了解由T6SS.提供效应器附着和传递的机制.
- 为了揭示T6SS有机体对细菌掠食的完整结构.
主要方法:
- 使用X射线晶体学进行蛋白质结构分析.
- 研究PAAR蛋白在T6SS介导的分泌和杀死中的功能.
- 使用Vibrio cholerae和Acinetobacter baylyi作为模型生物.
主要成果:
- 来自PAAR (proline-alanine-alanine-arginine) 超级家族的蛋白质在VgrG尖端形成了一个利的形延伸.
- 在V. cholerae和A. baylyi.yi.中,PAAR蛋白对于T6SS介导的分泌和杀细胞至关重要.
- 晶体结构揭示了PAAR蛋白与VgrG类伙伴结合,使尖复合体利,并促进了效应器的附着.
结论:
- PAAR蛋白质是利T6SS VgrG尖端的关键组成部分,是捕食器械的关键组成部分.
- 为T6SS有机体提出了一个新模型,其中VgrG-PAAR尖峰复合体同时提供多个效应器.
- 这种机制允许有效且同时输送毒素,增强细菌掠食能力.
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