title: Composite active site of an ABC ATPase: MutS uses ATP to verify mismatch recognition and authorize DNA repair.
abstract: The MutS protein initiates DNA mismatch repair by recognizing mispaired and unpaired bases embedded in duplex DNA and activating endo- and exonucleases to remove the mismatch. Members of the MutS family also possess a conserved ATPase activity that belongs to the ATP binding cassette (ABC) superfamily. Here we report the crystal structure of a ternary complex of MutS-DNA-ADP and assays of initiation of mismatch repair in conjunction with perturbation of the composite ATPase active site by mutagenesis. These studies indicate that MutS has to bind both ATP and the mismatch DNA simultaneously in order to activate the other mismatch repair proteins. We propose that the MutS ATPase activity plays a proofreading role in DNA mismatch repair, verification of mismatch recognition, and authorization of repair.
authors.affiliation: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Junop
authors.forename: G
authors.initials: G
authors.lastname: Obmolova
authors.forename: K
authors.initials: K
authors.lastname: Rausch
authors.forename: P
authors.initials: P
authors.lastname: Hsieh
authors.forename: W
authors.initials: W
authors.lastname: Yang
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020137:Base Pair Mismatch / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D003461:Crystallography; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D029968:Escherichia coli Proteins; D006801:Humans; D006868:Hydrolysis; D000070956:MutL Proteins; D051719:MutS DNA Mismatch-Binding Protein; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C074770:MutL protein, E coli; D009692:Nucleic Acid Heteroduplexes; D000255:Adenosine Triphosphate; D004706:Endodeoxyribonucleases; C059682:methyl-directed mismatch repair protein, E coli; D000251:Adenosine Triphosphatases; D000070956:MutL Proteins; D051719:MutS DNA Mismatch-Binding Protein; C497175:MutS protein, E coli; D045643:DNA Repair Enzymes