title: Yeast xrs2 binds DNA and helps target rad50 and mre11 to DNA ends.
abstract: Saccharomyces cerevisiae Rad50, Mre11, and Xrs2 proteins are involved in homologous recombination, non-homologous end-joining, DNA damage checkpoint signaling, and telomere maintenance. These proteins form a stable complex that has nuclease, DNA binding, and DNA end recognition activities. Of the components of the Rad50.Mre11.Xrs2 complex, Xrs2 is the least characterized. The available evidence is consistent with the idea that Xrs2 recruits other protein factors in reactions that pertain to the biological functions of the Rad50.Mre11.Xrs2 complex. Here we present biochemical evidence that Xrs2 has an associated DNA-binding activity that is specific for DNA structures. We also define the contributions of Xrs2 to the activities of the Rad50.Mre11.Xrs2 complex. Importantly, we demonstrate that Xrs2 is critical for targeting of Rad50 and Mre11 to DNA ends. Thus, Xrs2 likely plays a direct role in the engagement of DNA substrates by the Rad50. Mre11.Xrs2 complex in various biological processes.
authors.affiliation: University of Texas Health Science Center, Department of Molecular Medicine, Institute of Biotechnology, San Antonio, Texas 78245, USA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Trujillo
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Roh
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Stephen
authors.initials: S
authors.lastname: Van Komen
authors.forename: Alan
authors.initials: A
authors.lastname: Tomkinson
authors.forename: Patrick
authors.initials: P
authors.lastname: Sung
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001483:Base Sequence; D004265:DNA Helicases; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C086929:XRS2 protein, S cerevisiae; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C076225:RAD5 protein, S cerevisiae; D004265:DNA Helicases