Nuclease activities in a complex of human recombination and DNA repair factors Rad50, Mre11, and p95.
Genetic studies in yeast have indicated a role of the RAD50 and MRE11 genes in homologous recombination, telomere length maintenance, and DNA repair processes. Here, we purify from nuclear extract of Raji cells a complex consisting of human Rad50, Mre11, and another protein factor with a size of about 95 kDa (p95), which is likely to be Nibrin, the protein encoded by the gene mutated in Nijmegen breakage syndrome. We show that the Rad50-Mre11-p95 complex possesses manganese-dependent single-stranded DNA endonuclease and 3' to 5' exonuclease activities. These nuclease activities are likely to be important for recombination, repair, and genomic stability.
Department of Molecular Medicine/Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245-3207, USA.
K M
KM
Trujillo
S S
SS
Yuan
E Y
EY
Lee
P
P
Sung
D017766:Acid Anhydride Hydrolases; D018797:Cell Cycle Proteins / Q000378:metabolism*; D004260:DNA Repair; D045643:DNA Repair Enzymes; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D006801:Humans; D000076228:MRE11 Homologue Protein; D046911:Macromolecular Substances; D008970:Molecular Weight; D009687:Nuclear Proteins; D014407:Tumor Cells, Cultured
D018797:Cell Cycle Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C121766:MRE11 protein, human; D046911:Macromolecular Substances; C112156:NBN protein, human; D009687:Nuclear Proteins; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D000076228:MRE11 Homologue Protein; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes