通过dCas12f-σE-RNAP复合体进行RNA引导转录的结构基础
Renjian Xiao1,2, Florian T Hoffmann3,2, Dan Xie1
1Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA.
bioRxiv : the preprint server for biology
|July 15, 2025
概括
这项研究揭示了RNA引导蛋白如何通过确定新型转录启动系统的结构来激活基因表达. 这些发现揭示了细菌基因调节和可编程控制的新机制.
科学领域:
- 分子生物学分子生物学
- 微生物学 微生物学
- 生物化学 生物化学
背景情况:
- 由RNA引导的蛋白质通过与RNA聚合酶 (RNAP) 相互作用来调节细菌中的基因表达.
- 核酶死Cas12f (dCas12f) 同类物通过西格玛因子 (σE) 激活基因表达,但机制尚不清楚.
研究的目的:
- 通过dCas12f-σE系统阐明RNA引导转录激活的分子机制.
- 为了确定dCas12f介导的基因激活的结构基础.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定高分辨率结构.
- 多个dCas12f-σE复合体状态的结构分析,包括DNA结合和RNAP全酶复合体.
主要成果:
- 揭示了一种新的RNA引导转录启动模式.
- 捕获的dCas12f-σE-RNAP全酶复合物的结构与DNA结合.
- 经过RNA导向DNA结合的证明,在R循环下游的mRNA合成中招募 σE-RNAP.
- 显示的CRISPR-Cas准取代了正规的促进器识别 (-35元素) 并通过不寻常的相互作用稳定了-10元素.
结论:
- 提供了高分辨率的结构洞察力,了解一个意想不到的RNA引导转录机制.
- 扩大对细菌基因调节和CRISPR-Cas功能的理解.
- 开辟了开发可编程转录控制系统的新途径.
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