title: Mismatch-containing oligonucleotide duplexes bound by the E. coli mutS-encoded protein.
abstract: The binding of the mutS gene product, a protein involved in at least two E. coli mismatch correction pathways, to a series of synthetic DNA duplexes containing mismatches or mismatch analogues of the purine/pyrimidine type was studied in order to establish whether a correlation exists between the recognition of these mispairs and the efficiency of their correction in vivo. Experiments using nitrocellulose filter binding or band-shift assays revealed that duplexes containing a G/T mismatch or its analogues I/T and DI/T were bound by the protein with affinities correlating to the efficiency of their repair in vivo. In contrast, the A/C mismatch, contained within the same sequence, was bound only poorly, despite being efficiently corrected in vivo. The analogues of the A/C mispair, uncorrected in vivo, were not detectably bound under the conditions of these assays.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001667:Binding, Competitive; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases; D011755:Pyrophosphatases
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D009692:Nucleic Acid Heteroduplexes; D009841:Oligonucleotides; D010744:Phosphoric Monoester Hydrolases; D011755:Pyrophosphatases; C052211:mutT protein, E coli