Scholarlink

<p>Argonaute proteins (Agos) play essential roles in nucleic acid targeting across life domains. While eukaryotic Agos (eAgos) utilize small-interfering RNAs (siRNAs) or microRNAs (miRNAs) for RNA interference, the mechanisms driving prokaryotic Agos (pAgos) in bacterial defense remain underexplored. Here, we characterize the mesophilic pAgo from <i>Clostridium perfringens</i> (CpAgo), which exhibits robust guide-independent and DNA-guided activity at 37 °C. CpAgo efficiently degrades plasmids and structured RNAs into small fragments, generating DNA fragments that serve as guides for subsequent cleavage. Cryo-electron microscopy reveals a positively-charged PAZ nucleotide-binding pocket, critical for both guide-dependent and guide-independent substrate recognition and cleavage. Structural analysis identifies CpAgo’s dimerization as a prerequisite for catalytic activity, supporting both nucleic acid degradation and targeted action. Functional assays in <i>Escherichia coli</i> demonstrate CpAgo’s role in bacterial defense by mediating plasmid degradation and DNA-guided cleavage. These findings position CpAgo as a critical component of prokaryotic immunity and a promising tool for biotechnology.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The PAZ pocket and dimerization drive CpAgo’s guide-independent and DNA-guided dual catalysis

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年7月17日

查看全文
  • Yuchan Liu,
  • Jiasu Zhang,
  • Ji Liu,
  • Shengchun Zhang,
  • Linfeng An,
  • Wenbing Xie,
  • Kaiming Zhang,
  • Shanshan Li

摘要

Argonaute proteins (Agos) play essential roles in nucleic acid targeting across life domains. While eukaryotic Agos (eAgos) utilize small-interfering RNAs (siRNAs) or microRNAs (miRNAs) for RNA interference, the mechanisms driving prokaryotic Agos (pAgos) in bacterial defense remain underexplored. Here, we characterize the mesophilic pAgo from Clostridium perfringens (CpAgo), which exhibits robust guide-independent and DNA-guided activity at 37 °C. CpAgo efficiently degrades plasmids and structured RNAs into small fragments, generating DNA fragments that serve as guides for subsequent cleavage. Cryo-electron microscopy reveals a positively-charged PAZ nucleotide-binding pocket, critical for both guide-dependent and guide-independent substrate recognition and cleavage. Structural analysis identifies CpAgo’s dimerization as a prerequisite for catalytic activity, supporting both nucleic acid degradation and targeted action. Functional assays in Escherichia coli demonstrate CpAgo’s role in bacterial defense by mediating plasmid degradation and DNA-guided cleavage. These findings position CpAgo as a critical component of prokaryotic immunity and a promising tool for biotechnology.