title: Enzymatic and chemical probing of an S1 nuclease-sensitive site upstream from the human CFTR gene.
abstract: Similar purine/pyrimidine mirror repeat (PMR) DNA sequences have been identified in the 5'-flanking regions of the human cystic fibrosis transmembrane conductance regulator (hCFTR) and mucin (hMUC1) genes, and supercoiled (but not linearized) plasmids containing these promoter regions were previously shown to be sensitive to digestion by S1 nuclease. The PMR element derived from the hCFTR promoter region is now sub-cloned and characterized at nucleotide resolution with respect to its reactivity toward nucleases S1 and P1, and toward the chemical probes dimethyl sulfate, chloroacetaldehyde, diethylpyrocarbonate and osmium tetroxide. These probes confirm the presence, at pH 4.5 (but not at pH 7.1), of a non-B-DNA structure. This non-B-DNA structure is distinct from H-DNA, because enzymatic and chemical probing detect single-stranded character in the absence of a stable intramolecular triple helix or extruded purine strand.
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha 68198-6805.
authors.forename: C D
authors.initials: CD
authors.lastname: McDonald
authors.forename: M A
authors.initials: MA
authors.lastname: Hollingsworth
authors.forename: L J
authors.initials: LJ
authors.lastname: Maher
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018118:Chloride Channels / Q000235:genetics*; D003550:Cystic Fibrosis / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004247:DNA / Q000737:chemistry / Q000235:genetics*; D017931:DNA Primers; D004278:DNA, Superhelical; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D018396:Mucin-1; D009077:Mucins / Q000235:genetics; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases
chemical_list: C505032:CFTR protein, human; D018118:Chloride Channels; D017931:DNA Primers; D004278:DNA, Superhelical; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D018396:Mucin-1; D009077:Mucins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004247:DNA; D015719:Single-Strand Specific DNA and RNA Endonucleases