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细菌Argonaute核酸酶可进行DNA靶向与干扰
2020-08-01 17:05

俄罗斯科学院Andrey Kulbachinskiy等研究人员合作发现,一种细菌Argonaute核酸酶可进行DNA靶向与干扰。2020年7月30日,《自然》在线发表了这一成果。

研究人员测试了来自丁酸梭菌(CbAgo)Argonaute核酸酶的体内活性。研究人员证明,CbAgo靶向多拷贝遗传元件,并抑制质粒的传播和噬菌体的感染。CbAgo诱导同源序列之间的DNA干扰,并在目标DNA的双链断裂处触发DNA降解。用特定于位点的小DNA向导加载CbAgo取决于其固有的内切核酸酶活性和细胞双链断裂修复机制。
 
据报道,在CRISPR适应过程中获得新的间隔子存在类似的相互作用,并且在CRISPR-Cas系统中丰富了编码pAgo核酸酶的原核基因组。这些结果确定了产生DNA干扰向导的分子机制,并提出了原核防御系统识别外来核酸的通用原理。
 
保守的Argonaute蛋白家族的成员使用小RNA向导来寻找其mRNA靶标,从而调节基因表达并抑制真核生物中的移动遗传元件。Argonaute也存在于许多细菌和古细菌物种中。与真核蛋白不同,一些研究过的原核Argonautes使用小型DNA向导来切割DNA,这一过程被称为DNA干扰。但是,人们对DNA干扰的天然功能和靶标知之甚少,并且DNA向导产生和靶标识别的机制仍然未知。
 
附:英文原文

Title: DNA targeting and interference by a bacterial Argonaute nuclease

Author: Anton Kuzmenko, Anastasiya Oguienko, Daria Esyunina, Denis Yudin, Mayya Petrova, Alina Kudinova, Olga Maslova, Maria Ninova, Sergei Ryazansky, David Leach, Alexei A. Aravin, Andrey Kulbachinskiy

Issue&Volume: 2020-07-30

Abstract: Members of the conserved Argonaute protein family use small RNA guides to find their mRNA targets to regulate gene expression and suppress mobile genetic elements in eukaryotes1,2. Argonautes are also present in many bacterial and archaeal species3–5. Unlike eukaryotic proteins, several studied prokaryotic Argonautes use small DNA guides to cleave DNA, a process dubbed DNA interference6–10. However, the natural functions and targets of DNA interference are poorly understood, and the mechanisms of DNA guide generation and target discrimination remain unknown. Here, we studied the in vivo activities of a bacterial Argonaute nuclease from Clostridium butyricum (CbAgo). We demonstrated that CbAgo targets multicopy genetic elements and suppresses propagation of plasmids and infection by phages. CbAgo induces DNA interference between homologous sequences and triggers DNA degradation at double-strand breaks in the target DNA. Loading of CbAgo with locus-specific small DNA guides depends on both its intrinsic endonuclease activity and the cellular double-strand break repair machinery. A similar interplay was reported for acquisition of new spacers during CRISPR adaptation, and prokaryotic genomes encoding pAgo nucleases are enriched in CRISPR-Cas systems. These results identify molecular mechanisms that generate guides for DNA interference and suggest common principles of recognition of foreign nucleic acids by prokaryotic defense systems.

DOI: 10.1038/s41586-020-2605-1

Source: https://www.nature.com/articles/s41586-020-2605-1

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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