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单链DNA驱动 σ 子单元加载到菌株RNA聚合酶上,以解锁启动-竞争性构造
Rishi Kishore Vishwakarma1,2, Nils Marechal3, Zakia Morichaud1
1Institut de Recherche en Infectiologie de Montpellier, Univ Montpellier, CNRS, Montpellier 34293, France.
Nucleic acids research
|April 16, 2025
概括
与细菌RNA聚合酶 (RNAP) 结合的单链DNA (-10 ssDNA) 指导着关键的结构变化. 这种涉及西格玛 (σ) 子单元的机制对于启动转录和形成开放促进体复合体 (RPo) 是必不可少的.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 微生物学 微生物学
背景情况:
- 转录启动是一个由RNA聚合酶 (RNAP) 和其西格玛 (σ) 子单元调节的基本生物过程.
- 开放促进体复合体 (RPo) 的形成涉及DNA解,这是一个关键的步骤,其精确的机制尚未完全理解.
- 细菌RNAP利用σ子单元来识别促进子-10元素并启动DNA解.
研究的目的:
- 为了研究Mycobacterium结核病RNAP在与-10个单链DNA (-10 ssDNA) 片段结合时的构造变化.
- 阐明 σ 子单元在转录启动过程中调解 RNAP 构造动态中的作用.
- 为了揭示ssDNA引导RNAP成熟的机制.
主要方法:
- 单分子福斯特共振能量转移 (smFRET) 用于监测构造变化.
- 低温电子显微镜 (cryo-EM) 用于确定高分辨率结构.
- 生物化学测试用于研究蛋白质-DNA相互作用.
主要成果:
- -10 ssDNA结合诱导 σ子单元加载到RNAP的DNA/RNA通道上.
- 这种结合事件触发了RNAP关闭和解,这对于RPO形成至关重要.
- 确定了 σ 子单元是 RNAP 构造动态的一个关键调节器.
结论:
- 单链DNA作为指南,促进RNAP成熟和转录启动所需的形状变化.
- σ亚单元在调节RNAP构造动态中起着关键作用,以应对DNA结合.
- 这项研究提供了对Mycobacterium tuberculosis转录启动的机制性见解.
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