Download MendeleyStructural basis for dual DNA and RNA specificity of the G-quadruplex-resolving DEAH-box helicase DHX36.
Banco, M.T., Paul, T., Jiang, J., Myong, S., Ferre-D'Amare, A.R.(2025) Cell Rep 44: 116136-116136
- PubMed: 40833853
- DOI: https://doi.org/10.1016/j.celrep.2025.116136
- Primary Citation of Related Structures:
8VX8 - PubMed Abstract:
DEAH-box helicases, which share a structurally conserved ATPase core, function in all facets of eukaryotic gene expression. While most helicases are highly specialized for their substrates, DHX36 (DEAH-box helicase 36) resolves both DNA and RNA G-quadruplexes. To elucidate the molecular basis of this versatility, we have determined cryo-electron microscopy structures of bovine DHX36 bound to a three-tier RNA G-quadruplex and a six-tier DNA G-quadruplex at 2.6 and 3.4 Å resolution, respectively. Kinetic and smFRET characterizations of structure-guided mutants indicate a key role for the RecA2 domain of the helicase core in DNA vs. RNA discrimination. Furthermore, our structures show that a sequence-divergent RecA2 domain surface loop synergizes with a DHX36-specific N-terminal extension to orthogonally recognize features that specify G-quadruplexes over other nucleic acid structures. Our analysis suggests that recognizing their folded substrates by DEAH-box helicases may generally involve ornamentations of their structural cores acting synergistically with specialized peripheral elements.
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Organizational Affiliation:
