Scholarlink

<p>Human Suv3 is a dimeric helicase that collaborates with the exoribonuclease PNPase to mediate RNA decay and surveillance in mitochondria. Despite its pivotal role in maintaining mitochondrial homeostasis, the molecular mechanism underlying Suv3-mediated RNA unwinding has remained elusive. Here, we present near-atomic-resolution cryogenic electron microscopy structures of Suv3 captured in four functional states: the apo form, two binary complexes with ADP and single-stranded RNA (ssRNA), and a ternary complex with ssRNA and an ATP analog (AMP-PNP). These structures reveal an unexpected asymmetric dimeric organization, in which only one of the two protomers engages in the initial binding of ADP, ssRNA, or both ssRNA and AMP-PNP. Complementary biochemical analyses demonstrate that Suv3 dimerization significantly enhances RNA-binding and unwinding efficiency in an ATP-hydrolysis-dependent manner. Together, these findings provide key insights into the dimeric architecture of Suv3 and establish a mechanistic framework for its coordinated function in processive RNA unwinding.</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

Asymmetric dimeric assembly of Suv3 helicase facilitates processive RNA unwinding

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月15日

查看全文
  • Malay Patra,
  • Monika Jain,
  • Yi-Ching Li,
  • Yi-Ping Chen,
  • Bagher Golzarroshan,
  • Hanna S. Yuan

摘要

Human Suv3 is a dimeric helicase that collaborates with the exoribonuclease PNPase to mediate RNA decay and surveillance in mitochondria. Despite its pivotal role in maintaining mitochondrial homeostasis, the molecular mechanism underlying Suv3-mediated RNA unwinding has remained elusive. Here, we present near-atomic-resolution cryogenic electron microscopy structures of Suv3 captured in four functional states: the apo form, two binary complexes with ADP and single-stranded RNA (ssRNA), and a ternary complex with ssRNA and an ATP analog (AMP-PNP). These structures reveal an unexpected asymmetric dimeric organization, in which only one of the two protomers engages in the initial binding of ADP, ssRNA, or both ssRNA and AMP-PNP. Complementary biochemical analyses demonstrate that Suv3 dimerization significantly enhances RNA-binding and unwinding efficiency in an ATP-hydrolysis-dependent manner. Together, these findings provide key insights into the dimeric architecture of Suv3 and establish a mechanistic framework for its coordinated function in processive RNA unwinding.