通过AcrIIA11抑制Cas9的机制
Kaylee E Dillard1, Hongshan Zhang1, Lianne Z Dubbs1
1Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, United States.
Nucleic acids research
|April 25, 2025
概括
一种新的抗CRISPR蛋白,AcrIIA11,通过减缓它们的DNA搜索和分裂,广泛抑制多个Cas9酶. 这一发现揭示了CRISPR-Cas军备竞赛中一种新的动力抑制机制.
科学领域:
- 分子生物学分子生物学
- 微生物遗传学 微生物遗传学
- 生物化学 生物化学
背景情况:
- 克里斯普尔-卡斯系统在原核生物中提供适应性免疫力.
- 移动基因元素编码抗CRISPR蛋白 (Acrs) 来逃避CRISPR-Cas监控.
- Acrs通常通过多种机制抑制特定的Cas效应体.
研究的目的:
- 描述AcrIIA11的抑制机制和频谱.
- 为了研究AcrIIA11和各种Cas9 ортолог之间的相互作用.
- 为了阐明由AcrIIA11.11抑制CRISPR-Cas的动态方面.
主要方法:
- 在体外生化测试以评估Cas9抑制.
- 单分子成像用于观察蛋白质-DNA相互作用.
- 负染色电子显微镜用于结构分析.
- 在人类细胞中进行功能性检测.
主要成果:
- AcrIIA11可以抑制Streptococcus pyogenes,Staphylococcus aureus和Francisella novicida Cas9s. 这三种菌株的发生.
- AcrIIA11减少了Cas9在非特异性DNA上的扩散,阻碍了目标搜索.
- 该AcrIIA11:Cas9复合体结合了非目标部位,并减缓了目标部位的DNA裂变.
- 结构分析显示了AcrIIA11:Cas9复合物的1:1石化学.
结论:
- AcrIIA11对不同的Cas9变体表现出广泛的抑制.
- AcrIIA11采用一种动力学机制,影响DNA搜索和分裂.
- 这项研究扩大了已知的反CRISPR机制和它们在进化上的影响.
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