Inhibition of CRISPR-Cas9 ribonucleoprotein complex assembly by anti-CRISPR AcrIIC2
Inhibition of CRISPR-Cas9 ribonucleoprotein complex assembly by anti-CRISPR AcrIIC2
复制标题
抗 CRISPR AcrIIC2 抑制 CRISPR-Cas9 核糖核蛋白复合物组装
DOI：
10.1038/s41467-019-10577-3
复制
发表时间：
2019-06-26
影响因子：
16.6
通讯作者：
Maxwell, Karen L.
中科院分区：
文献类型：
--
作者：
Thavalingam, Annoj;Cheng, Zhi;Maxwell, Karen L.
CRISPR-Cas适应性免疫系统的功能是保护细菌免受外来遗传因子的入侵。CRISPR-Cas9系统已被广泛采用作为一种强大的基因组编辑工具，而噬菌体编码的抑制剂，称为抗CRISPR，提供了一种调节其活性的方法。在这里，我们报告了抗CRISPR蛋白AcrIIC 2Nmealone和与Nme 1Cas 9复合的晶体结构。我们证明AcrIIC 2Nme通过与带正电荷的桥螺旋相互作用抑制Cas9，从而阻止sgRNA加载。体内噬菌斑试验和体外DNA切割试验表明，AcrIIC 2N介导其活性是通过一个大的负电性表面。这项工作表明，抗CRISPR活性可以通过抑制Cas9复合物组装来介导。
CRISPR-Cas adaptive immune systems function to protect bacteria from invasion by foreign genetic elements. The CRISPR-Cas9 system has been widely adopted as a powerful genome-editing tool, and phage-encoded inhibitors, known as anti-CRISPRs, offer a means of regulating its activity. Here, we report the crystal structures of anti-CRISPR protein AcrIIC2Nmealone and in complex with Nme1Cas9. We demonstrate that AcrIIC2Nmeinhibits Cas9 through interactions with the positively charged bridge helix, thereby preventing sgRNA loading. In vivo phage plaque assays and in vitro DNA cleavage assays show that AcrIIC2Nmemediates its activity through a large electronegative surface. This work shows that anti-CRISPR activity can be mediated through the inhibition of Cas9 complex assembly.