title: A nuclear factor that binds purine-rich, single-stranded oligonucleotides derived from S1-sensitive elements upstream of the CFTR gene and the MUC1 gene.
abstract: We have identified two regions of non-random purine/pyrimidine strand asymmetry that were nearly identical in sequence in the 5' flanking (promoter) regions of the human cystic fibrosis transmembrane conductance regulator (CFTR) gene and the human MUC1 gene. These regions contain perfect mirror repeat elements, a sequence motif previously found to be associated with the formation of H-DNA conformations. In this report we demonstrate that a single-stranded non-B DNA conformation exists at low pH in supercoiled plasmids containing the similar mirror repeat elements, and that S1 nuclease digestion maps the single-stranded region to the position of the mirror repeats. In addition, we identify a nuclear protein of approximately 27 kD that binds to single-stranded oligonucleotides corresponding to the purine-rich strand of this region, but not to the pyrimidine-rich strands or to double-stranded oligonucleotides with corresponding purine/pyrimidine strand asymmetry.
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198-6805.
authors.forename: M A
authors.initials: MA
authors.lastname: Hollingsworth
authors.forename: C
authors.initials: C
authors.lastname: Closken
authors.forename: A
authors.initials: A
authors.lastname: Harris
authors.forename: C D
authors.initials: CD
authors.lastname: McDonald
authors.forename: G S
authors.initials: GS
authors.lastname: Pahwa
authors.forename: L J
authors.initials: LJ
authors.lastname: Maher
mesh_terms: D001483:Base Sequence; D001667:Binding, Competitive; D003550:Cystic Fibrosis / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D018396:Mucin-1; D009077:Mucins / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism*; D011687:Purines / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
chemical_list: C505032:CFTR protein, human; D004277:DNA, Single-Stranded; D008562:Membrane Glycoproteins; D018396:Mucin-1; D009077:Mucins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011687:Purines; D015534:Trans-Activators; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D015719:Single-Strand Specific DNA and RNA Endonucleases