实时观察RNA聚合酶II转录的启动
Furqan M Fazal1, Cong A Meng2, Kenji Murakami3
1Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Nature
|September 3, 2015
概括
RNA聚合酶II转录启动涉及一个大型预启动复合体 (PIC). 与之前的观点相反,这种复合物迅速打开一个广泛的DNA泡进行转录,使促进物能够逃脱.
科学领域:
- 分子生物学
- 生物化学
- 遗传学
背景情况:
- RNA聚合酶II转录是一个复杂的过程.
- 转录启动涉及多种蛋白质因子和DNA相互作用.
- 之前的模型提出在启动过程中有限的DNA解.
研究的目的:
- 调查转录启动的实时动态.
- 挑战现有的转录泡形成和扫描模型.
- 为了阐明促销者逃逸的机制.
主要方法:
- 来自Saccharomyces cerevisiae的32种蛋白质预启动复合物的组装.
- 使用光学笔实时观察转录启动.
- 对DNA解,转录合成和促进体逃逸的分析.
主要成果:
- 预启动复合物迅速打开了一个扩展的转录泡 (平均85个基对).
- 转录合成发生在扩展泡的长度上.
- 发起人逃离失败导致泡崩和徒劳的扫描.
结论:
- 转录因子IIH在启动过程中驱动快速和广泛的DNA解.
- 这个过程涉及到比以前想象的更长的成绩单的合成.
- 由于促销器逃逸失败和泡崩,可以发生虚假扫描.
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