A guanine-flipping and sequestration mechanism for G-quadruplex unwinding by RecQ helicases.
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ABSTRACT:
SUBMITTER: Voter AF
PROVIDER: S-EPMC6180126 | biostudies-literature | 2018 Oct
REPOSITORIES: biostudies-literature
Publications
A guanine-flipping and sequestration mechanism for G-quadruplex unwinding by RecQ helicases.
Voter Andrew F AF Qiu Yupeng Y Tippana Ramreddy R Myong Sua S Keck James L JL
Nature communications 20181010 1
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, indic ...[more]
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