The identification and characterization of a G4-DNA resolvase activity.

Journal Article (Journal Article)

There is increasing evidence that four-stranded Hoogsteen-bonded DNA structures, G4-DNA, play an important role in cellular processes such as meiosis and recombination. The Hoogsteen-bonded G4-DNA is thermodynamically more stable than duplex DNA, and many guanine-rich genomic DNA sequences with the ability to form G4-DNA have been identified. A protein-dependent activity that resolves G4-DNA into single-stranded DNA has been identified in human placental tissue. The resolvase activity was purified from any apparent nuclease activity and is dependent on NTP hydrolysis and MgCl2. Resolvase activity is optimal with 5 mM MgCl2. The Vmax/Km of ATP is 0. 055%/min/microM, higher than the Vmax/Km of the other dNTPs. The products of the resolvase reaction are unmodified single-stranded DNA. The resolvase is not a duplex DNA helicase or a topoisomerase II activity and does not unwind Hoogsteen-bonded triplex DNA. Resolvase is a novel activity that unwinds stable G4-DNA structures using a dNTP-dependent mechanism producing unmodified single-stranded DNA. Potential in vivo roles for this G4-DNA resolvase activity are discussed.

Full Text

Duke Authors

Cited Authors

  • Harrington, C; Lan, Y; Akman, SA

Published Date

  • September 26, 1997

Published In

Volume / Issue

  • 272 / 39

Start / End Page

  • 24631 - 24636

PubMed ID

  • 9305932

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.272.39.24631


  • eng

Conference Location

  • United States