人类领先链的结构 Polε-PCNA全酶
Qing He1, Feng Wang1, Nina Y Yao2
1Department of Structural Biology, Van Andel Institute, Grand Rapids, MI, USA.
Nature communications
|September 8, 2024
概括
人类DNA聚合酶epsilon (Polε) 通过一种新的三点接口与PCNA进行相互作用. 这种结构揭示了Polε如何结合PCNA来调节DNA合成.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 细胞DNA复制依赖于复制性聚合酶,包括Polε和Polδ,这些聚合酶在与增殖细胞核抗原 (PCNA) 结时表现出增强的过程性.
- 虽然酵母Pole的催化域结构已知,但其与任何真核生物中的PCNA相互作用的分子机制仍然未被阐明.
研究的目的:
- 为了确定人类DNA聚合酶epsilon (Polε) 和PCNA之间的相互作用的结构基础.
- 阐明这种相互作用调节DNA合成和核酸结合的机制.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定人类Pole-PCNA-DNA复合体在两个不同的功能状态中的结构:输入核酸结合和核酸交换.
- 综合体的详细结构分析,以确定关键的交互接口和结构变化.
主要成果:
- 两个冷EM结构揭示了Polε催化域和PCNA三元体之间的独特的三点接口.
- 这种接口涉及PIP-motif,P-domain和Polε的指域,每一个都与不同的PCNA原质体接触.
- 结构比较突出了指指域围绕P域的 [4Fe-4S] 集群旋转的构造变化,调节核酸结合和交换.
结论:
- 聚和PCNA之间的多点相互作用对于稳定的复合体形成至关重要,并且可以防止在复制过程中招募其他PCNA相互作用蛋白.
- 观察到的结构动态为Polε如何调节DNA合成进展和核酸结合提供了机械的见解.
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