可重新编程的RNA向CRISPR系统是从RNA毒素-抗毒素进化而来的
Shai Zilberzwige-Tal1, Han Altae-Tran2, Soumya Kannan1
1Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research at MIT, Cambridge, MA 02139, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Cell
|February 19, 2025
概括
研究人员追踪了针对RNA的CRISPR-Cas13系统的演变,发现它们可能起源于流产性感染 (AbiF) 毒素-抗毒素系统. 这项研究揭示了促使进化转型的关键结构变化.
科学领域:
- 微生物学
- 分子生物学
- 进化生物学
背景情况:
- CRISPR 系统对于 prokaryotes 的适应性免疫是至关重要的.
- 导致RNA引导的CRISPR系统的进化途径,特别是Cas13,尚未完全理解.
- 了解CRISPR进化为基因组防御机制提供了洞察力.
研究的目的:
- 为了确定RNA向CRISPR-Cas13系统的进化祖先.
- 描述进化中间体Cas13e及其与AbiF的关系.
- 阐明AbiF和Cas13系统之间的结构和功能差异.
主要方法:
- 综合序列和结构进化跟踪.
- 对Cas13e和AbiF的生化表征
- 用冷电子显微镜 (冷电子显微镜) 来确定AbiF的结构.
主要成果:
- Cas13系统可能是从AbiF进化而来的,AbiF是一种与流产性感染相关的毒素-抗毒素系统.
- 一种名为Cas13e的微型Cas13被确定为一种进化中间体.
- AbiF作为一种具有RNA抗毒素的毒素-抗毒素系统,与Cas13的RNA指导RNA向不同.
- 与Cas13s相比,AbiF的冷EM结构显示出结构上的差异.
- 将从AbiF转变为CRISPR的关键结构变化绘制为地图.
结论:
- 这项研究为向RNA的CRISPR-Cas13系统提供了明确的进化轨迹.
- AbiF是Cas13的一个可信的前体,突出了功能和结构的转变.
- 这些发现加深了我们对可编程RNA指导系统的演变的理解.
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