The RecQ helicase Sgs1 drives ATP-dependent disruption of Rad51 filaments

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

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


DNA helicases of the RecQ family are conserved among the three domains of life and play essential roles in genome maintenance. Mutations in several human RecQ helicases lead to diseases that are marked by cancer predisposition. The Saccharomyces cerevisiae RecQ helicase Sgs1 is orthologous to human BLM, defects in which cause the cancer-prone Bloom's Syndrome. Here, we use single-molecule imaging to provide a quantitative mechanistic understanding of Sgs1 activities on single stranded DNA (ssDNA), which is a central intermediate in all aspects of DNA metabolism. We show that Sgs1 acts upon ssDNA bound by either replication protein A (RPA) or the recombinase Rad51. Surprisingly, we find that Sgs1 utilizes a novel motor mechanism for disrupting ssDNA intermediates bound by the recombinase protein Rad51. The ability of Sgs1 to disrupt Rad51-ssDNA filaments may explain some of the defects engendered by RECQ helicase deficiencies in human cells.

Original languageEnglish (US)
Pages (from-to)4694-4706
Number of pages13
JournalNucleic acids research
Issue number9
StatePublished - May 21 2019

ASJC Scopus subject areas

  • Genetics


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