title: Dss1 interaction with Brh2 as a regulatory mechanism for recombinational repair.
abstract: Brh2, the BRCA2 ortholog in Ustilago maydis, enables recombinational repair of DNA by controlling Rad51 and is in turn regulated by Dss1. Interplay with Rad51 is conducted via the BRC element located in the N-terminal region of the protein and through an unrelated domain, CRE, at the C terminus. Mutation in either BRC or CRE severely reduces functional activity, but repair deficiency of the brh2 mutant can be complemented by expressing BRC and CRE on different molecules. This intermolecular complementation is dependent upon the presence of Dss1. Brh2 molecules associate through the region overlapping with the Dss1-interacting domain to form at least dimer-sized complexes, which in turn, can be dissociated by Dss1 to monomer. We propose that cooperation between BRC and CRE domains and the Dss1-provoked dissociation of Brh2 complexes are requisite features of Brh2's molecular mechanism.
authors.affiliation: Department of Microbiology and Immunology, Cornell University Weill Medical College, 1300 York Avenue, New York, NY 10021, USA.
authors.forename: Qingwen
authors.initials: Q
authors.lastname: Zhou
authors.forename: Milorad
authors.initials: M
authors.lastname: Kojic
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Cao
authors.forename: Michael
authors.initials: M
authors.lastname: Lisby
authors.forename: Nayef A
authors.initials: NA
authors.lastname: Mazloum
authors.forename: William K
authors.initials: WK
authors.lastname: Holloman
mesh_terms: D004260:DNA Repair; D019281:Dimerization; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D017354:Point Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051135:Rad51 Recombinase / Q000737:chemistry*; D011995:Recombination, Genetic; D014588:Ustilago / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D051135:Rad51 Recombinase