Regulatory control of Sgs1 and Dna2 during eukaryotic DNA end resection

Chaoyou Xue, Weibin Wang, J. Brooks Crickard, Corentin J. Moevus, Youngho Kwon, Patrick Sung, Eric C. Greene

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


In the repair of DNA double-strand breaks by homologous recombination, the DNA break ends must first be processed into 3' singlestrand DNA overhangs. In budding yeast, end processing requires the helicase Sgs1 (BLM in humans), the nuclease/helicase Dna2, Top3-Rmi1, and replication protein A (RPA). Here, we use singlemolecule imaging to visualize Sgs1-dependent end processing in real-time. We show that Sgs1 is recruited to DNA ends through Top3-Rmi1-dependent or -independent means, and in both cases Sgs1 is maintained in an immoble state at the DNA ends. Importantly, the addition of Dna2 triggers processive Sgs1 translocation, but DNA resection only occurs when RPA is also present. We also demonstrate that the Sgs1-Dna2-Top3-Rmi1-RPA ensemble can efficiently disrupt nucleosomes, and that Sgs1 itself possesses nucleosome remodeling activity. Together, these results shed light on the regulatory interplay among conserved protein factors that mediate the nucleolytic processing of DNA ends in preparation for homologous recombination-mediated chromosome damage repair.

Original languageEnglish (US)
Pages (from-to)6091-6100
Number of pages10
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number13
StatePublished - 2019


  • DNA end resection
  • DNA repair
  • Helicase
  • Homologous recombination
  • Single molecule

ASJC Scopus subject areas

  • General


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