title: Direct observation of three conformations of MutS protein regulated by adenine nucleotides.
abstract: Mismatched base-pairs, which are caused by either DNA replication errors, DNA damage or genetic recombination, are repaired by the mismatch-repair system. The MutS protein, a component of the mismatch-repair system, recognizes mismatched base-pairs in DNA, and its DNA-binding activity is affected by ATP and ADP. Here, we show that the MutS protein from Thermus thermophilus HB8 can have three different conformations in solution, based on direct observations made by small-angle X-ray scattering. The conformation of MutS in solution is drastically influenced by the presence of ADP and ATP; the ATP-bound form has the most compact conformation, the ADP-bound form the most stretched, and the nucleotide-free form has a conformation intermediate between the two. Based on these findings, we conclude that the DNA-binding activity of MutS may depend on conformational changes triggered by both the binding and hydrolysis of ATP.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Kataoka
authors.forename: H
authors.initials: H
authors.lastname: Kamikubo
authors.forename: S
authors.initials: S
authors.lastname: Kuramitsu
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D019943:Amino Acid Substitution / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020137:Base Pair Mismatch; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004260:DNA Repair; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D006868:Hydrolysis; D008958:Models, Molecular; D008970:Molecular Weight; D051719:MutS DNA Mismatch-Binding Protein; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D017433:Protein Structure, Secondary; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism; D012542:Scattering, Radiation; D012996:Solutions; D013329:Structure-Activity Relationship; D017356:Synchrotrons; D016963:Thermus thermophilus / Q000201:enzymology* / Q000235:genetics; D014965:X-Rays
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012996:Solutions; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D051719:MutS DNA Mismatch-Binding Protein; C497175:MutS protein, E coli; D006180:Proton-Translocating ATPases