在细菌转录中 σ54 位移和促进物逃逸的结构基础
Forson Gao1, Fuzhou Ye1, Bowen Zhang1
1Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London SW7 2AZ, United Kingdom.
概括
通过sigma 54 (σ54) 启动细菌转录,涉及RNA聚合酶 (RNAP) 和DNA缩. 结构研究揭示了 σ54 和 DNA 相互作用的变化,使 RNAP 能够逃脱促进体并开始延长.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 遗传学 是一个
背景情况:
- 基因转录是一种由RNA聚合酶 (RNAP) 和西格玛 (σ) 因子调节的基本细胞过程.
- 细菌转录启动涉及 σ 因素招募RNAP到促进DNA,形成RNA合成的开放复合体.
- 虽然 σ70 机制已知,但 σ54 从初始转录到延长的过渡仍然不清楚.
研究的目的:
- 阐明通过细菌的σ54因子介导的转录启动期间促进体逃逸的结构机制.
- 了解RNA聚合酶 (RNAP) -σ54复合体如何从初始转录过渡到过程延长.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来捕获RNAP-σ54复合物的快照.
- 对于具有越来越长RNA分子的复合体,确定了结构.
- 分析的重点是与转录泡动态和s54-DNA相互作用相关的结构变化.
主要成果:
- 低温EM结构揭示了转录泡和DNA缩中的动态变化,随着RNA的扩展.
- 转录泡的扩大和DNA缩减少了σ54-DNA相互作用.
- 这些结构重组促进RNAP从s54和上游DNA释放.
结论:
- 这项研究揭示了 σ54 依存转录中促进子逃逸的结构基础.
- DNA缩和转录泡动力学是驱动RNAP释放延长的关键机制.
- 研究结果提供了细菌中压力反应基因调节的见解.
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