Processing of DNA structures via DNA unwinding and branch migration by the S. cerevisiae Mph1 protein

DNA Repair (Amst). 2011 Oct 10;10(10):1034-43. doi: 10.1016/j.dnarep.2011.08.002. Epub 2011 Aug 30.


The budding yeast Mph1 protein, the putative ortholog of human FANCM, possesses a 3' to 5' DNA helicase activity and is capable of disrupting the D-loop structure to suppress chromosome arm crossovers in mitotic homologous recombination. Similar to FANCM, genetic studies have implicated Mph1 in DNA replication fork repair. Consistent with this genetic finding, we show here that Mph1 is able to mediate replication fork reversal, and to process the Holliday junction via DNA branch migration. Moreover, Mph1 unwinds 3' and 5' DNA Flap structures that bear key features of the D-loop. These biochemical results not only provide validation for a role of Mph1 in the repair of damaged replication forks, but they also offer mechanistic insights as to its ability to efficiently disrupt the D-loop intermediate.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • DEAD-box RNA Helicases / genetics
  • DEAD-box RNA Helicases / metabolism*
  • DNA / chemistry*
  • DNA / genetics
  • DNA / metabolism
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • DNA Repair / genetics
  • DNA Replication / genetics*
  • DNA, Cruciform / chemistry
  • DNA, Cruciform / genetics
  • Homologous Recombination
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*


  • DNA, Cruciform
  • Saccharomyces cerevisiae Proteins
  • DNA
  • MPH1 protein, S cerevisiae
  • DNA Helicases
  • DEAD-box RNA Helicases