title: Active Control of Repetitive Structural Transitions between Replication Forks and Holliday Junctions by Werner Syndrome Helicase.
abstract: The reactivation of stalled DNA replication via fork regression invokes Holliday junction formation, branch migration, and the recovery of the replication fork after DNA repair or error-free DNA synthesis. The coordination mechanism for these DNA structural transitions by molecular motors, however, remains unclear. Here we perform single-molecule fluorescence experiments with Werner syndrome protein (WRN) and model replication forks. The Holliday junction is readily formed once the lagging arm is unwound, and migrated unidirectionally with 3.2 ± 0.03 bases/s velocity. The recovery of the replication fork was controlled by branch migration reversal of WRN, resulting in repetitive fork regression. The Holliday junction formation, branch migration, and migration direction reversal are all ATP dependent, revealing that WRN uses the energy of ATP hydrolysis to actively coordinate the structural transitions of DNA.
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea; Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea; National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Soochul
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea; Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea; National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea; Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea; National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Sangwoon
authors.initials: S
authors.lastname: Yoo
authors.affiliation: Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Kulikowicz
authors.affiliation: Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: Vilhelm A
authors.initials: VA
authors.lastname: Bohr
authors.affiliation: Department of Life Sciences, University of Ulsan, Ulsan 680-749, Republic of Korea. Electronic address: bbccahn@mail.ulsan.ac.kr.
authors.forename: Byungchan
authors.initials: B
authors.lastname: Ahn
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea; Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea; National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, Republic of Korea; Department of Biophysics and Chemical Biology, Seoul National University, Seoul 08826, Republic of Korea. Electronic address: shohng@snu.ac.kr.
authors.forename: Sungchul
authors.initials: S
authors.lastname: Hohng
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D020029:Base Pairing; D002232:Carbocyanines / Q000737:chemistry; D004261:DNA Replication; D045566:DNA, Cruciform / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D061987:Sf9 Cells; D000072760:Single Molecule Imaging; D018411:Spodoptera; D000071657:Werner Syndrome Helicase / Q000235:genetics / Q000378:metabolism*
chemical_list: D002232:Carbocyanines; D045566:DNA, Cruciform; D005456:Fluorescent Dyes; D011993:Recombinant Fusion Proteins; C089187:cyanine dye 3; C085321:cyanine dye 5; D000255:Adenosine Triphosphate; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase
keywords: replication fork regression; single-molecule FRET; werner syndrome helicase