复制诱导的DNA二次结构驱动了分叉解和断裂
Sophie L Williams1, Corella S Casas-Delucchi1, Federica Raguseo2,3
1Genome Replication Lab, Division of Cancer Biology, Institute of Cancer Research, Chester Beatty Laboratories, London, UK.
The EMBO journal
|October 2, 2023
概括
像G-四复合体 (G4s) 和介质动机 (iMs) 这样的DNA二次结构可以阻止DNA复制. 皮夫1酶能够解决这些结构,防止基因组的不稳定性和复制压力.
科学领域:
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
- 基因组学就是基因组学.
背景情况:
- 在人类基因组中,大量的DNA二次结构,包括G-四重复合体 (G4s) 和间隔动机 (iMs),是普遍存在的.
- 这些结构起着生理作用,但也会阻碍DNA复制,损害基因组的稳定性.
- 通过G4s和IMs干扰复制的精确机制仍然不完全理解.
研究的目的:
- 调查G四重复 (G4s) 和间隔动机 (iMs) 如何影响DNA复制.
- 阐明这些DNA结构引起的复制停止的机制基础.
- 为了确定参与复制分叉被G4s和IMs所停滞的解决方案的因素.
主要方法:
- 使用生理学上相关的结构形成序列重建DNA复制.
- 在固态纳米孔中检测单分子结构.
- 结构稳定性和形成概率的综合遗传和生物物理特征.
- 在解决停滞的复制分叉时分析酶活性.
主要成果:
- 一次G4或IM足以阻止DNA复制.
- 这些结构在复制过程中形成,通过纳米孔分析检测到.
- 复制停止是由于合成受损和酶-聚合酶脱而导致的;IMs也会导致新生的DNA断裂.
- 只有Pif1螺旋酶,而不是Rrm3,Sgs1,Chl1或Hrq1,可以拯救停滞的叉子.
结论:
- G4s和IMs是内源复制压力的来源,直接抑制DNA复制.
- 结构稳定性和形成概率是复制分叉停止的关键决定因素.
- Pif1是解决与复制相关的G4和iM结构的关键酶.
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