title: Recombinational repair in yeast: functional interactions between Rad51 and Rad54 proteins.
abstract: Rad51p is a eukaryotic homolog of RecA, the central homologous pairing and strand exchange protein in Escherichia coli. Rad54p belongs to the Swi2p/Snf2p family of DNA-stimulated ATPases. Both proteins are also important members of the RAD52 group which controls recombinational DNA damage repair of double-strand breaks and other DNA lesions in Saccharomyces cerevisiae. Here we demonstrate by genetic, molecular and biochemical criteria that Rad51 and Rad54 proteins interact. Strikingly, overexpression of Rad54p can functionally suppress the UV and methyl methanesulfonate sensitivity caused by a deletion of the RAD51 gene. However, no suppression was observed for the defects of rad51 cells in the repair of gamma-ray-induced DNA damage, mating type switching or spontaneous hetero-allelic recombination. This suppression is genetically dependent on the presence of two other members of the recombinational repair group, RAD55 and RAD57. Our data provide compelling evidence that Rad51 and Rad54 proteins interact in vivo and that this interaction is functionally important for recombinational DNA damage repair. As both proteins are conserved throughout evolution from yeasts to humans, a similar protein-protein interaction may be expected in other organisms.
authors.affiliation: Institute of General Microbiology, Bern, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Clever
authors.forename: H
authors.initials: H
authors.lastname: Interthal
authors.forename: J
authors.initials: J
authors.lastname: Schmuckli-Maurer
authors.forename: J
authors.initials: J
authors.lastname: King
authors.forename: M
authors.initials: M
authors.lastname: Sigrist
authors.forename: W D
authors.initials: WD
authors.lastname: Heyer
mesh_terms: D000251:Adenosine Triphosphatases; D015153:Blotting, Western; D004249:DNA Damage; D004265:DNA Helicases; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004271:DNA, Fungal / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D051135:Rad51 Recombinase; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C087191:RAD55 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D000251:Adenosine Triphosphatases; C075468:RAD54 protein, S cerevisiae; C071451:RAD57 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes