Work

Asymmetric dimeric assembly of Suv3 helicase facilitates processive RNA unwinding

Year: 2026

Type: article

Abstract: 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. Human Suv3 is a mitochondrial helicase essential for RNA decay. Here, the authors present cryo-EM structures of Suv3 in multiple functional states, revealing an asymmetric dimeric architecture that coordinates ATP hydrolysis for processive RNA unwinding.

Source: Nature Communications

DOI: 10.1038/s41467-026-71901-2

Authors: Malay Patra, Monika Jain, Yi-Ching Li, Yi-Ping Chen, Bagher Golzarroshan, Hanna S. Yuan

Institutions: Institute of Molecular Biology, Academia Sinica, Academia Sinica

Language: English

Topic: RNA Research and Splicing

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $6,990

Funder: Academia Sinica