通过转录RNA聚合酶II进行CPD损伤识别
Florian Brueckner1, Ulrich Hennecke, Thomas Carell
1Munich Center for Integrated Protein Science CiPS, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
概括
细胞在转录合修复 (TCR) 过程中阻断RNA聚合酶II (Pol II) 通过错误地将尿素纳入相反的DNA损伤. 这种停滞对于DNA修复至关重要,防止聚合酶的进展,直到病变被移除.
科学领域:
- 分子生物学分子生物学
- DNA 修复机制的修复机制
- 生物化学 生物化学
背景情况:
- 转录合修复 (TCR) 对于去除DNA损伤至关重要,例如紫外线诱导的环丁胺二聚体 (CPD).
- RNA聚合酶II (Pol II) 通过在DNA损伤部位停滞,在TCR中发挥中心作用.
研究的目的:
- 阐明真核细胞TCR最初阶段的基于结构的机制:CPD诱导的Pol II的停滞.
- 了解像CPD这样的DNA病变如何阻碍聚合酶的进展.
主要方法:
- 对RNA聚合酶II的结构分析在循环butanpyrimidine二元体中停滞.
- 调查核酸错误融入在聚合酶停滞中的作用.
主要成果:
- 在转录的DNA链中,一个CPD进入了Pol II活性位点,将尿素错误纳入新生的RNA.
- 这种尿素错误结合阻断了聚合酶转位,导致停滞.
- 用腺替换尿素可以绕过CPD,证实CPD导向的错误整合是停滞的关键.
- 停滞的聚合酶形状保持不变,病变无法进入.
结论:
- 在CPD中,Pol II的停滞是由病变导向的尿素错误整合介导的,而不是聚合酶中的全变化.
- 停滞不前的复合物促进了用于病变切除的修复因子的非全性招募.
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