第四类分泌系统的外膜复合物的结构
Vidya Chandran1, Rémi Fronzes, Stéphane Duquerroy
1Institute of Structural and Molecular Biology, University College London and Birkbeck College, Malet Street, London WC1E 7HX, UK.
Nature
|December 1, 2009
概括
第四类分泌系统是细菌纳米机器. 这项研究揭示了外膜通道结构,确定VirB10是跨越两种细菌膜的关键蛋白质.
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:
- 第四类分泌系统 (T4SS) 是格拉姆阴性细菌中必不可少的纳米机器,覆盖内外膜.
- 包含VirB7,VirB9和VirB10蛋白质的T4SS核心复合体对于基质转位至关重要.
- 了解外膜成分的结构对于破译分泌机制至关重要.
研究的目的:
- 为了确定T4SS外膜复合体的高分辨率结构.
- 阐明单个蛋白质,特别是VirB10在形成外膜通道中的作用.
- 调查道调节的结构基础.
主要方法:
- 采用X射线晶体学来确定外膜复合物的结构 (大约0.6MDa).
- 用冷电子显微镜 (cryo-EM) 数据进行比较结构分析.
- 生物化学和生物物理技术被用来描述该复杂的特征.
主要成果:
- 确定了由VirB7,VirB9和VirB10组成的完整外膜复合物的晶体结构.
- 鉴定出VirB10是外膜通道的中心组成部分,具有独特的疏水性双螺旋转膜区域.
- 这项工作确立了VirB10作为已知穿越T4SS.内两个细菌膜的唯一蛋白质.
- 结构性比较揭示了与道关相关的潜在形状变化.
结论:
- 解决的结构为T4SS外膜通道的架构提供了前所未有的洞察力.
- 维尔B10在形成跨膜孔的过程中起着至关重要的作用,对T4SS功能至关重要.
- 该通道的形状可塑性表明,有调节基质通道的机制.
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