title: The budding yeast Mei5-Sae3 complex interacts with Rad51 and preferentially binds a DNA fork structure.
abstract: Meiotic homologous recombination in Saccharomyces cerevisiae involves formation of nucleoprotein filaments of Rad51 and Dmc1 that mediate DNA strand exchange between homologous chromosomes. The Mei5-Sae3 protein complex functions as a recombination mediator to promote nucleation of the Dmc1 recombinase onto replication protein A-coated single-stranded DNA. Here, we have expressed and purified the Mei5 protein, Sae3 protein and the Mei5-Sae3 complex for biochemical studies. We show the Mei5-Sae3 complex preferentially binds a fork-like DNA substrate to 3' overhanging DNA, single-stranded DNA or double-stranded DNA. We demonstrate that Mei5 confers DNA binding activity to the Mei5-Sae3 complex. We determined Mei5-Sae3 interacts with the Rad51 recombinase through the N-terminal domain of Mei5. Unlike Rad52, Mei5-Sae3 lacks recombination mediator activity for Rad51. Importantly, we find that the Mei5-Sae3 complex does not harbor single-strand DNA annealing activity. These properties of the Mei5-Sae3 complex distinguishes it from the Rad52 protein, which serves as the mediator of Rad51 and is involved in the single-strand DNA annealing pathway of homologous recombination.
authors.affiliation: Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA.
authors.forename: Amanda F
authors.initials: AF
authors.lastname: Say
authors.forename: LeAnna L
authors.initials: LL
authors.lastname: Ledford
authors.forename: Deepti
authors.initials: D
authors.lastname: Sharma
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Singh
authors.forename: Wing-Kit
authors.initials: WK
authors.lastname: Leung
authors.forename: Hilarie A
authors.initials: HA
authors.lastname: Sehorn
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsubouchi
authors.forename: Patrick
authors.initials: P
authors.lastname: Sung
authors.forename: Michael G
authors.initials: MG
authors.lastname: Sehorn
mesh_terms: D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*; D045522:Recombinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004277:DNA, Single-Stranded; C495980:Mei5 protein, S cerevisiae; D045522:Recombinases; C107851:SAE3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase