Affinity of mismatch-binding protein MutS for heteroduplexes containing different mismatches.
We have used bandshift analysis to measure the interaction between the Escherichia coli mismatch-binding protein MutS and synthetic DNA fragments containing all possible DNA mismatches as well as an unpaired T (DeltaT). The order of affinity is found to be DeltaT>GT>GG>AA approximately TT approximately TC>CA>GA>CC>GC. We find that the affinity for GT mismatches is affected by the flanking sequence and decreases in the order G(n)C(n)>(GC)(n)>A(n)T(n)>(AT)(n). Studies with base analogues show good binding to phiT (where phi represents 1',2'-dideoxyribose), but much weaker binding to Gphi.
Division of Biochemistry and Molecular Biology, School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton S016 7PX, UK.
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D000251:Adenosine Triphosphatases; D001426:Bacterial Proteins / Q000378:metabolism*; D020137:Base Pair Mismatch; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D029968:Escherichia coli Proteins; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D051719:MutS DNA Mismatch-Binding Protein; D009692:Nucleic Acid Heteroduplexes / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism; D013941:Thymine / Q000031:analogs & derivatives / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D009692:Nucleic Acid Heteroduplexes; D009841:Oligonucleotides; D006147:Guanine; D004247:DNA; D000251:Adenosine Triphosphatases; D051719:MutS DNA Mismatch-Binding Protein; C497175:MutS protein, E coli; D013941:Thymine