通过终端ATPase的转位独立RNA聚合酶失活的步骤
Nelly Said1, Tarek Hilal2, Nicholas D Sunday3
1Laboratory of Structural Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
概括
蛋白质复合体Rho (ρ) 因子通过捕获RNA聚合酶来终止基因转录. 冷EM结构揭示了Rho如何与NusA和NusG蛋白相互作用以解DNA并释放RNA,从而停止转录.
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- 转录终止对于基因调节至关重要,但机制尚不清楚.
- 因子依赖终结涉及与转录机制相互作用的Rho (ρ) 等蛋白质因子.
研究的目的:
- 阐明Rho-依赖转录终结的结构机制.
- 在终止过程中可视化Rho,Nusa,NusG和RNA聚合酶之间的动态相互作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定高分辨率结构.
- 用于分析蛋白质与核酸相互作用和功能后果的生物化学测试.
主要成果:
- 在转录终结复合体中捕获Rho (ρ) 与Nusa,NusG和RNA聚合酶相互作用的冷EM结构.
- 观察到Rho的六边形环结构捕获和解DNA,而Nusa则对RNA进行隔离.
- 一个涉及Nusa旋转和Rho开的顺序机制导致RNA释放和转录失活.
结论:
- 罗依赖转录终止涉及多阶段的异构机制.
- 罗利用结构策略来捕获和禁用转录复合体,这种机制可能会在终结因子中保存.
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