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A guanine-flipping and sequestration mechanism for G-quadruplex unwinding by RecQ helicases.
- Source :
-
Nature communications [Nat Commun] 2018 Oct 10; Vol. 9 (1), pp. 4201. Date of Electronic Publication: 2018 Oct 10. - Publication Year :
- 2018
-
Abstract
- Homeostatic regulation of G-quadruplexes (G4s), four-stranded structures that can form in guanine-rich nucleic acids, requires G4 unwinding helicases. The mechanisms that mediate G4 unwinding remain unknown. We report the structure of a bacterial RecQ DNA helicase bound to resolved G4 DNA. Unexpectedly, a guanine base from the unwound G4 is sequestered within a guanine-specific binding pocket. Disruption of the pocket in RecQ blocks G4 unwinding, but not G4 binding or duplex DNA unwinding, indicating its essential role in structure-specific G4 resolution. A novel guanine-flipping and sequestration model that may be applicable to other G4-resolving helicases emerges from these studies.
Details
- Language :
- English
- ISSN :
- 2041-1723
- Volume :
- 9
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature communications
- Publication Type :
- Academic Journal
- Accession number :
- 30305632
- Full Text :
- https://doi.org/10.1038/s41467-018-06751-8