对核细胞体中DNA糖酶AAG介导的基因切除的结构和机制见解
Lvqin Zheng1,2, Bin Tsai1, Ning Gao3
1State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
Cell discovery
|June 20, 2023
概括
通过利用结构性可塑性,DNA糖化酶AAG通过利用核体上受损的DNA获取. 它使DNA和核细胞变形,以达到损坏的部位,无论它们的可访问性如何.
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:
- 基切除修复始于DNA糖酶的参与.
- 核细胞体中的真核生物基因组包装阻碍了DNA的可访问性.
- 在核体上寻找DNA糖酶基质的机制尚不清楚.
研究的目的:
- 阐明DNA糖酶AAG与受损的核体DNA相互作用的结构机制.
- 了解AAG如何克服核细胞所施加的可访问性障碍.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于用脱氧氨 (DI) 确定核体的结构.
- 用冷电磁波测定AAG核体复合体的结构.
- 酶基质相互作用和核酶体动态的结构分析.
主要成果:
- 脱氧氨素 (DI) 单独在全球范围内扰乱核体DNA,削弱DNA-海斯相互作用并增加DNA输出/输入灵活性.
- AAG利用核体可塑性并诱导局部DNA变形以形成稳定的复合体.
- AAG采用了包括扭曲增强,寄存器转移和核细胞组开放在内的策略,以在各种位置 (暴露,封闭,埋藏) 访问DI.
结论:
- 这项研究揭示了DI诱导的核细胞体结构动态的分子基础.
- 它阐明了AAG如何以不同的可访问性访问核细胞上受损的DNA部位.
- 这些发现为DNA修复机制提供了洞察力,在染色质结构的背景下.
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