在DmDcr-2寡合体上R2D2和Loqs-PD协同调节的结构机制
Ting Deng1, Shichen Su1, Xun Yuan2
1State Key Laboratory of Genetic Engineering, Collaborative Innovation Centre of Genetics and Development, Department of Biochemistry and Biophysics, Institute of Plant Biology, School of Life Sciences, Fudan University, 200438, Shanghai, China.
Nature communications
|August 26, 2023
概括
小干扰RNAs (siRNAs) 对RNA干扰至关重要. 新的冷EM结构揭示了R2D2和Loqs-PD共因子如何同时结合Dicer-2 (DmDcr-2),形成siRNA处理所必需的纤维.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 遗传学 是一个
背景情况:
- 小干扰RNAs (siRNAs) 是RNA干扰 (RNAi) 的关键,这是基因沉默和真核生物病毒防御的重要机制.
- 在Drosophila melanogaster中,Dicer-2 (DmDcr-2) 酶将双链RNA (dsRNA) 处理成siRNA,其中Loqs-PD和R2D2辅因子调节其功能.
- 由于缺乏结构数据,R2D2和Loqs-PD与DmDcr-2的同时相互作用及其结构基础仍然不清楚.
研究的目的:
- 在siRNA成熟过程中,阐明DmDcr-2及其辅因子R2D2和Loqs-PD的结构机制.
- 调查R2D2和Loqs-PD是否可以同时和无干扰地与DmDcr-2结合.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定DmDcr-2/R2D2/Loqs-PD复合体与不同长度的dsRNA结合的结构.
- 分析了复合体的绑定接口和寡合状态.
主要成果:
- 低温-EM结构显示R2D2和Loqs-PD与DmDcr-2的不同区域结合,表明它们具有同时且不干扰的相互作用.
- 观察到DmDcr-2/R2D2/Loqs-PD复合体形成大型寡合体并组装成纤维.
- 这些寡合物的形成和脱聚合与ATP水解相结合,这表明了动态调节机制.
结论:
- 通过同时结合,R2D2和Loqs-PD可以协同调节DmDcr-2活动,为它们在siRNA处理中的作用提供结构基础.
- 通过ATP水解调节的观察到的寡合化和纤维形成,突出了控制RNAi中的DmDcr-2功能的新机制.
- 这些发现为DMDcr-2复合体的结构动力学提供了关键的见解,进步了我们对RNA沉默路径的理解.
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