一个RNA聚合酶促进体的结构溶解中介解DNA
Hande Boyaci1, James Chen1, Rolf Jansen2
1Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY, USA.
Nature
|January 11, 2019
概括
研究人员使用冷EM可视化RNA聚合酶 (RNAP) 促进物化的中间体. 关键的结构特征,分叉环2和开关2,控制基因转录的DNA开放.
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- 转录启动由RNA聚合酶 (RNAP) 调节,形成一个开放的促进体复合体.
- 这一过程涉及解DNA并将模板链加载到RNAP活性部位.
- 在开放复合物形成过程中形成具有未知结构的过渡中间体.
研究的目的:
- 确定细菌RNAP促进体DNA复合物的结构,包括部分化的中间体.
- 通过RNAP阐明促进体DNA化的结构机制.
- 了解特定RNAP结构特征在调节DNA解中的作用.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来获得高分辨率的结构.
- 对细菌RNAP促进体DNA复合体进行了分析.
- 部分化中间体的结构得到了解决.
主要成果:
- 在RNAP裂隙内发生的促体溶解的晚期阶段.
- 分叉环2和交换机2被确定为限制DNA进入活性部位的关键结构元素.
- 这些结构解释了RNAP门对于模板DNA输入的必要性.
结论:
- 晚期促进体融阶段发生在RNAP裂隙内,由叉环2和开关2介导.
- 这些结构特征在调节DNA解和RNAP开方面起着至关重要的作用.
- 促进DNA开放的常见机制可能存在于所有生命领域,促进基因表达.
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