title: Differential ATP binding and intrinsic ATP hydrolysis by amino-terminal domains of the yeast Mlh1 and Pms1 proteins.
abstract: MutL homologs belong to a family of proteins that share a conserved ATP binding site. We demonstrate that amino-terminal domains of the yeast MutL homologs Mlh1 and Pms1 required for DNA mismatch repair both possess independent, intrinsic ATPase activities. Amino acid substitutions in the conserved ATP binding sites concomitantly reduce ATP binding, ATP hydrolysis, and DNA mismatch repair in vivo. The ATPase activities are weak, consistent with the hypothesis that ATP binding is primarily responsible for modulating interactions with other MMR components. Three approaches, ATP hydrolysis assays, limited proteolysis protection, and equilibrium dialysis, provide evidence that the amino-terminal domain of Mlh1 binds ATP with >10-fold higher affinity than does the amino-terminal domain of Pms1. This is consistent with a model wherein ATP may first bind to Mlh1, resulting in events that permit ATP binding to Pms1 and later steps in DNA mismatch repair.
authors.affiliation: Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hall
authors.forename: Polina V
authors.initials: PV
authors.lastname: Shcherbakova
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Kunkel
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D020137:Base Pair Mismatch; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D005656:Fungal Proteins; C088859:MLH1 protein, S cerevisiae; C074770:MutL protein, E coli; C088858:PMS1 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins