细胞CMG酶激活的机制
Max E Douglas1, Ferdos Abid Ali2, Alessandro Costa2
1Chromosome Replication Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
Nature
|March 1, 2018
概括
细胞DNA复制的启动包括两个阶段. 发射因子激活微染色体维护 (MCM) 复合体到两个Cdc45-MCM-GINS (CMG) 基酶,确保精确的DNA复制.
科学领域:
- 分子生物学
- 生物化学
- 遗传学
背景情况:
- 细胞DNA的复制始于两个阶段:MCM复合组合和激发因子介导的激活.
- 在G1阶段,MCM复合体在原始DNA周围形成双六合体.
- 在 S 阶段,燃烧因子将 MCM 双六合体转化为两个活性 CMG 螺旋酶.
研究的目的:
- 阐明真核复制螺旋酶激活的机制.
- 详细说明ADP/ATP结合和水解在CMG酶组合和激活中的作用.
- 了解CMG螺旋酶转移的过程及其对复合体的建立的影响.
主要方法:
- 生物化学试验研究MCM复合物和激发因子的相互作用.
- 核酸结合 (ADP/ATP) 和水解的分析.
- 在体外实验中监测DNA解和酶激活.
- 研究McM10在酶激活中的作用.
主要成果:
- 在形成双六合体后,MCM复合体仍然与ADP结合.
- 燃烧因子触发ADP释放,而ATP结合促进了稳定的CMG组装.
- CMG组装涉及DNA解和将双六合体分成两个不活跃的螺旋酶.
- 麦克米10和ATP水解进一步解DNA并激活螺旋酶.
- 激活的CMG螺旋酶以N终端的方向转移,互相通过.
结论:
- 这项研究揭示了真核生物复制螺旋酶激活的详细机制.
- 在CMG组装和激活过程中,ADP释放和ATP结合至关重要.
- N-终端-第一转移机制确保了有效的复制体建立.
- 这一过程提供了双向DNA复制的安全机制.
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