从Cas9的引导RNA相互作用域开始，通过迭代的结构和序列同源性挖掘，该团队在噬菌体和寄生细菌中鉴定了一个RNA引导的DNA靶向蛋白家族。每个系统由串联间隔引导RNA （TIGR）阵列和含有Nop结构域的TIGR相关（Tas）蛋白组成，有时是HNH （TasH）或RuvC （TasR）核酸酶结构域。该课题组发现TIGR阵列被加工成36-nt rna (tigRNAs)，通过串联间隔器靶向机制直接序列特异性DNA结合。TasR可以被重新编程以进行精确的DNA切割，包括在人类细胞中。TasR的结构显示出与盒C/D snoRNPs和IS110 RNA引导转座的惊人相似性，为了解各种RNA引导系统的进化提供了见解。
据了解，RNA引导系统提供了显著的多功能性，实现了多种生物功能。
附：英文原文
Title: TIGR-Tas: A family of modular RNA-guided DNA-targeting systems in prokaryotes and their viruses
Author: Guilhem Faure, Makoto Saito, Max E. Wilkinson, Natalia Quinones-Olvera, Peiyu Xu, Daniel Flam-Shepherd, Stephanie Kim, Nishith Reddy, Shiyou Zhu, Lilia Evgeniou, Eugene V. Koonin, Rhiannon K. Macrae, Feng Zhang
Issue&Volume: 2025-02-27
Abstract: RNA-guided systems provide remarkable versatility, enabling diverse biological functions. Through iterative structural and sequence homology-based mining starting with a guide RNA-interaction domain of Cas9, we identified a family of RNA-guided DNA-targeting proteins in phage and parasitic bacteria. Each system consists of a Tandem Interspaced Guide RNA (TIGR) array and a TIGR-associated (Tas) protein containing a Nop domain, sometimes fused to HNH (TasH) or RuvC (TasR) nuclease domains. We show that TIGR arrays are processed into 36-nt RNAs (tigRNAs) that direct sequence-specific DNA binding through a tandem-spacer targeting mechanism. TasR can be reprogrammed for precise DNA cleavage, including in human cells. The structure of TasR reveals striking similarities to box C/D snoRNPs and IS110 RNA-guided transposases, providing insights into the evolution of diverse RNA-guided systems.
DOI: adv9789
Source: https://www.science.org/doi/10.1126/science.adv9789