title: Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination.
abstract: Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, "open," and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex.
authors.affiliation: DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK.
authors.forename: Martin R G
authors.initials: MRG
authors.lastname: Taylor
authors.affiliation: Department of Biology, Masaryk University, 62500 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, 62500 Brno, Czech Republic.
authors.forename: Mário
authors.initials: M
authors.lastname: Špírek
authors.affiliation: Section of Virology, Single Molecule Imaging Group and MRC Clinical Sciences Centre, Department of Medicine, Imperial College London, London W12 0NN, UK.
authors.forename: Kathy R
authors.initials: KR
authors.lastname: Chaurasiya
authors.affiliation: DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK; UCSF-Mission Bay, Genentech Hall S574, San Francisco, CA 94158, USA.
authors.forename: Jordan D
authors.initials: JD
authors.lastname: Ward
authors.affiliation: Electron Microscopy Science Technology Platform, Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London WC2A 3LY, UK.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Carzaniga
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
authors.forename: Xiong
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Egelman
authors.affiliation: Electron Microscopy Science Technology Platform, Lincoln's Inn Fields Laboratory, The Francis Crick Institute, London WC2A 3LY, UK.
authors.forename: Lucy M
authors.initials: LM
authors.lastname: Collinson
authors.affiliation: Section of Virology, Single Molecule Imaging Group and MRC Clinical Sciences Centre, Department of Medicine, Imperial College London, London W12 0NN, UK.
authors.forename: David
authors.initials: D
authors.lastname: Rueda
authors.affiliation: Department of Biology, Masaryk University, 62500 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital in Brno, 62500 Brno, Czech Republic; National Centre for Biomolecular Research, Masaryk University, 62500 Brno, Czech Republic. Electronic address: lkrejci@chemi.muni.cz.
authors.forename: Lumir
authors.initials: L
authors.lastname: Krejci
authors.affiliation: DNA Damage Response Laboratory, Clare Hall Laboratory, The Francis Crick Institute, South Mimms EN6 3LD, UK. Electronic address: simon.boulton@crick.ac.uk.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Boulton
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D059765:Homologous Recombination; D006801:Humans; D009154:Mutation; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D051135:Rad51 Recombinase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C109212:NUP42 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; C000602003:RFS-1 protein, C elegans; C000602004:RIP-1 protein, C elegans; D029701:Saccharomyces cerevisiae Proteins; D051135:Rad51 Recombinase; C495148:rad-51 protein, C elegans