Nature ( IF 50.5 ) Pub Date : 2023-04-05 , DOI: 10.1038/s41586-023-05826-x
Giedrius Sasnauskas 1 , Giedre Tamulaitiene 1 , Gytis Druteika 1 , Arturo Carabias 2 , Arunas Silanskas 1 , Darius Kazlauskas 1 , Česlovas Venclovas 1 , Guillermo Montoya 2 , Tautvydas Karvelis 1 , Virginijus Siksnys 1
The widespread TnpB proteins of IS200/IS605 transposon family have recently emerged as the smallest RNA-guided nucleases capable of targeted genome editing in eukaryotic cells1,2. Bioinformatic analysis identified TnpB proteins as the likely predecessors of Cas12 nucleases3,4,5, which along with Cas9 are widely used for targeted genome manipulation. Whereas Cas12 family nucleases are well characterized both biochemically and structurally6, the molecular mechanism of TnpB remains unknown. Here we present the cryogenic-electron microscopy structures of the Deinococcus radiodurans TnpB–reRNA (right-end transposon element-derived RNA) complex in DNA-bound and -free forms. The structures reveal the basic architecture of TnpB nuclease and the molecular mechanism for DNA target recognition and cleavage that is supported by biochemical experiments. Collectively, these results demonstrate that TnpB represents the minimal structural and functional core of the Cas12 protein family and provide a framework for developing TnpB-based genome editing tools.
中文翻译:
TnpB 结构揭示了 Cas12 核酸酶家族的最小功能核心
IS200/IS605 转座子家族中广泛存在的 TnpB 蛋白最近已成为能够在真核细胞中进行靶向基因组编辑的最小 RNA 引导核酸酶1,2。生物信息分析确定 TnpB 蛋白可能是 Cas12 核酸酶的前身3,4,5,它与 Cas9 一起广泛用于靶向基因组操作。尽管 Cas12 家族核酸酶在生化和结构上都得到了很好的表征6,但 TnpB 的分子机制仍然未知。在这里,我们展示了耐辐射奇球菌TnpB-reRNA(右端转座子元件衍生的 RNA)复合物的 DNA 结合和游离形式的低温电子显微镜结构。这些结构揭示了 TnpB 核酸酶的基本结构以及 DNA 靶标识别和切割的分子机制,并得到生化实验的支持。总的来说,这些结果表明 TnpB 代表了 Cas12 蛋白家族的最小结构和功能核心,并为开发基于 TnpB 的基因组编辑工具提供了框架。