9EI2 image
Deposition Date 2024-11-25
Release Date 2025-03-05
Last Version Date 2025-07-16
Entry Detail
PDB ID:
9EI2
Title:
Cryo-EM structure of Human RNA polymerase II Elongation Complex bound to an apo RECQL5 helicase (RECQL5 IRI Module focused-classified)
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Method Details:
Experimental Method:
Resolution:
2.80 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:DNA-directed RNA polymerase II subunit RPB1
Gene (Uniprot):POLR2A
Chain IDs:A
Chain Length:1970
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:ATP-dependent DNA helicase Q5
Gene (Uniprot):RECQL5
Chain IDs:B (auth: U)
Chain Length:991
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural insights into transcriptional regulation by the helicase RECQL5.
Nat.Struct.Mol.Biol. ? ? ? (2025)
PMID: 40624164 DOI: 10.1038/s41594-025-01611-8

Abstact

Transcription poses a major challenge for genome stability. The RECQL5 helicase helps safeguard genome integrity and is the only member of the human RecQ helicase family that directly binds to RNA polymerase II (Pol II) and affects its progression. While RECQL5 mitigates transcription stress in cells, the molecular mechanism underlying this phenomenon is unclear. Here, we use cryo-electron microscopy to determine the structures of stalled human Pol II elongation complexes (ECs) bound to RECQL5. Our structures reveal the molecular interactions stabilizing RECQL5 binding to the Pol II EC and highlight its role as a transcriptional roadblock. Additionally, we find that, in its nucleotide-free state, RECQL5 twists the downstream DNA in the EC and, upon nucleotide binding, undergoes a conformational change that allosterically induces Pol II toward a post-translocation state. We propose that this mechanism may help restart Pol II elongation and, therefore, contribute to reducing transcription stress.

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