通过AcrIIC4进行CRISPR-Cas9的抑制机制
Xuzichao Li1, Fumeng Liao1, Jiaqi Gao1
1State Key Laboratory of Experimental Hematology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Haihe Laboratory of Cell Ecosystem, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
Nucleic acids research
|August 17, 2023
概括
反CRISPR蛋白AcrIIC4通过锁定其REC2域来抑制Neisseria meningitidis Cas9 (NmeCas9),防止DNA结合和裂变. 这一发现为CRISPR-Cas调节和基因编辑工具开发提供了洞察力.
科学领域:
- 分子生物学分子生物学
- 微生物免疫 微生物免疫
- 结构生物学 结构生物学
背景情况:
- 克里斯普尔-卡斯系统为 prokaryotes 提供了对外基因元素的适应性免疫力.
- 抗CRISPR (Acr) 蛋白质是抵消CRISPR-Cas活动的病毒因素.
- 此前,对Neisseria meningitidis Cas9 (NmeCas9) 的AcrIIC4抑制机制尚不清楚.
研究的目的:
- 在生物化学和结构上阐明AcrIIC4对NmeCas9.9的抗CRISPR机制.
- 了解AcrIIC4如何与NmeCas9和sgRNA相互作用.
- 为开发Cas9基因编辑的监管工具提供基础.
主要方法:
- 生物化学测试以评估抑制活性.
- 结构研究 (可能是结晶学或冷EM) 来确定复杂的结构.
- 位点定向突变发生,以确定关键相互作用残留物.
主要成果:
- AcrIIC4形成了一个螺旋束,与NmeCas9和sgRNA的REC叶结合.
- AcrIIC4锁定了NmeCas9的REC2域,破坏了DNA结合和裂变.
- 在AcrIIC4-NmeCas9或AcrIIC4-sgRNA接口的突变显著减少抑制.
结论:
- AcrIIC4通过一种新的机制抑制NmeCas9,该机制涉及REC2域的结构锁定.
- 这些发现澄清了AcrIIC4介导的NmeCas9抑制的分子基础.
- 这项研究为可控制的基于Cas9的基因编辑技术的工程提供了信息.
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