title: Rad50 adenylate kinase activity regulates DNA tethering by Mre11/Rad50 complexes.
abstract: Mre11 and Rad50 are the catalytic components of a highly conserved DNA repair complex that functions in many aspects of DNA metabolism involving double-strand breaks. The ATPase domains in Rad50 are related to the ABC transporter family of ATPases, previously shown to share structural similarities with adenylate kinases. Here we demonstrate that Mre11/Rad50 complexes from three organisms catalyze the reversible adenylate kinase reaction in vitro. Mutation of the conserved signature motif reduces the adenylate kinase activity of Rad50 but does not reduce ATP hydrolysis. This mutant resembles a rad50 null strain with respect to meiosis and telomere maintenance in S. cerevisiae, correlating adenylate kinase activity with in vivo functions. An adenylate kinase inhibitor blocks Mre11/Rad50-dependent DNA tethering in vitro and in cell-free extracts, indicating that adenylate kinase activity by Mre11/Rad50 promotes DNA-DNA associations. We propose a model for Rad50 that incorporates both ATPase and adenylate kinase reactions as critical activities that regulate Rad50 functions.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Venugopal
authors.initials: V
authors.lastname: Bhaskara
authors.forename: Aude
authors.initials: A
authors.lastname: Dupré
authors.forename: Bettina
authors.initials: B
authors.lastname: Lengsfeld
authors.forename: Ben B
authors.initials: BB
authors.lastname: Hopkins
authors.forename: Angela
authors.initials: A
authors.lastname: Chan
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Jean
authors.initials: J
authors.lastname: Gautier
authors.forename: Virginia
authors.initials: V
authors.lastname: Zakian
authors.forename: Tanya T
authors.initials: TT
authors.lastname: Paull
mesh_terms: D017766:Acid Anhydride Hydrolases; D000225:Adenine / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000263:Adenylate Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D019843:Archaeal Proteins / Q000378:metabolism; D002384:Catalysis / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D045643:DNA Repair Enzymes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015226:Dinucleoside Phosphates / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005090:Exodeoxyribonucleases / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D000076228:MRE11 Homologue Protein; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D020027:Pyrococcus furiosus / Q000187:drug effects / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014981:Xenopus
chemical_list: D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; D015226:Dinucleoside Phosphates; D004791:Enzyme Inhibitors; C121766:MRE11 protein, human; D050505:Mutant Proteins; C086930:RAD50 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C012275:P(1),P(5)-di(adenosine-5'-)pentaphosphate; D000255:Adenosine Triphosphate; D004247:DNA; D000263:Adenylate Kinase; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D000076228:MRE11 Homologue Protein; C094191:MRE11 protein, S cerevisiae; C415985:Mre11 protein, archaeal; C415984:Rad50 protein, archaeal; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes; D000225:Adenine