title: Tid1/Rdh54 promotes dissociation of Dmc1 from nonrecombinogenic sites on meiotic chromatin.
abstract: The meiosis-specific recombinase Dmc1 plays a critical role in DNA strand exchange in budding yeast. Tid1/Rdh54, a member of the Swi2/Snf2 family of DNA translocases, has been shown to stimulate Dmc1-dependent recombination. Tid1and its budding yeast paralog Rad54 have a variety of biochemical activities that may contribute to their biological function. Here we demonstrate that Dmc1 can associate with chromatin in the absence of DNA double-strand breaks (DSBs), and Tid1 suppresses this association. Chromatin immunoprecipitation experiments indicate that an activity shared by Tid1 and Rad54 is required for normal assembly of Dmc1 at DSB sites in preparation for recombination. These results lead to a model in which the ATP hydrolysis-dependent DNA translocase activity of Tid1 acts to promote dissociation of Dmc1 from nonreombinogenic sites on chromatin, with Rad54 being able to substitute for this function in the absence of Tid1. The tendency of Dmc1 to form unproductive interactions with chromatin is proposed to be a consequence of the mechanism of strand exchange. The results raise the possibility that ATP hydrolysis-dependent disruption of nonproductive recombinase-DNA interactions is a feature shared with other homologous recombination systems.
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Illinois 60637, USA.
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Holzen
authors.forename: Parisha P
authors.initials: PP
authors.lastname: Shah
authors.forename: Heidi A
authors.initials: HA
authors.lastname: Olivares
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Bishop
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004265:DNA Helicases; D004260:DNA Repair; D045643:DNA Repair Enzymes; D026942:DNA Topoisomerases; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004734:Energy Metabolism; D005800:Genes, Fungal; D008540:Meiosis; D008954:Models, Biological; D009154:Mutation; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; C513033:DMC1 protein, S cerevisiae; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; D026942:DNA Topoisomerases; C541336:RDH54 protein, S cerevisiae; D045643:DNA Repair Enzymes