| Structural highlights
9i22 is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 2.42Å |
| Ligands: | , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
RECQ1_HUMAN DNA helicase that may play a role in the repair of DNA that is damaged by ultraviolet light or other mutagens. Exhibits a magnesium-dependent ATP-dependent DNA-helicase activity that unwinds single- and double-stranded DNA in a 3'-5' direction.[1] [2] [3]
Publication Abstract from PubMed
RECQ1, the most abundant RecQ helicase in human cells, is involved in telomere maintenance in ALT cells and plays a critical role in maintaining genomic integrity and stability. Here, we present five high-resolution crystal structures that systematically reveal a novel mechanism by which the RECQ1 helicase recognizes and regulates G-quadruplex (G4) DNA structures. Our results demonstrate that DNA binding induces intra-subunit rearrangement in RECQ1, transitioning it from a closed to an open conformation. This rearrangement alters the stability of the dimer interface. G4 recognition and unwinding are driven by coordinated interactions between the D1/D2 domains and the single-stranded DNA (ssDNA)-binding channel. This dual engagement aligns the G4 tetrad in a geometry favorable for unwinding. ATP hydrolysis facilitates ssDNA translocation, positioning the beta-hairpin to disrupt hydrogen bonds-unraveling G4 structures in a manner analogous to the unwinding of dsDNA. This study proposes a mechanistic model for RECQ1-mediated G4 unwinding and elucidates how RECQ1 recognizes and unwinds distinct DNA structures.
Structural mechanism of RECQ1 helicase in unfolding G-quadruplexes compared with duplex DNA.,Song ZY, Zhang X, Ai X, Huang LY, Hou XM, Fosse P, Liu NN, Mauffret O, Rety S, Xi XG Nucleic Acids Res. 2025 Sep 5;53(17):gkaf877. doi: 10.1093/nar/gkaf877. PMID:40966504[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Doherty KM, Sharma S, Uzdilla LA, Wilson TM, Cui S, Vindigni A, Brosh RM Jr. RECQ1 helicase interacts with human mismatch repair factors that regulate genetic recombination. J Biol Chem. 2005 Jul 29;280(30):28085-94. Epub 2005 May 9. PMID:15886194 doi:http://dx.doi.org/10.1074/jbc.M500265200
- ↑ Puranam KL, Blackshear PJ. Cloning and characterization of RECQL, a potential human homologue of the Escherichia coli DNA helicase RecQ. J Biol Chem. 1994 Nov 25;269(47):29838-45. PMID:7961977
- ↑ Seki M, Yanagisawa J, Kohda T, Sonoyama T, Ui M, Enomoto T. Purification of two DNA-dependent adenosinetriphosphatases having DNA helicase activity from HeLa cells and comparison of the properties of the two enzymes. J Biochem. 1994 Mar;115(3):523-31. PMID:8056767
- ↑ Song ZY, Zhang X, Ai X, Huang LY, Hou XM, Fossé P, Liu NN, Mauffret O, Réty S, Xi XG. Structural mechanism of RECQ1 helicase in unfolding G-quadruplexes compared with duplex DNA. Nucleic Acids Res. 2025 Sep 5;53(17):gkaf877. PMID:40966504 doi:10.1093/nar/gkaf877
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