title: Inhibition of restriction endonuclease cleavage via triple helix formation by homopyrimidine oligonucleotides.
abstract: A 17-mer homopyrimidine oligonucleotide was designed to bind to the major groove of SV40 DNA at a 17 base pair homopurine-homopyrimidine sequence via Hoogsteen base pairing. This sequence contains the recognition site for the class II-S restriction enzyme Ksp 632-I. The oligonucleotide was shown to inhibit enzymatic cleavage under conditions that allow for triple helix formation. Inhibition is sequence-specific and occurs in the micromolar concentration range. Triple helix formation by oligonucleotides opens new possibilities for sequence-specific regulation of gene expression.
authors.affiliation: Laboratoire de Biophysique, INSERM U.201, CNRS UA.481, Muséum National d'Histoire Naturelle, Paris, France.
authors.forename: J C
authors.initials: JC
authors.lastname: François
authors.forename: T
authors.initials: T
authors.lastname: Saison-Behmoaras
authors.forename: N T
authors.initials: NT
authors.lastname: Thuong
authors.forename: C
authors.initials: C
authors.lastname: Hélène
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004278:DNA, Superhelical / Q000235:genetics; D015252:Deoxyribonucleases, Type II Site-Specific / Q000037:antagonists & inhibitors*; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D009841:Oligonucleotides / Q000494:pharmacology*; D011742:Pyrimidine Nucleotides / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D013539:Simian virus 40 / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical; D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D011742:Pyrimidine Nucleotides; D011743:Pyrimidines; C057073:endodeoxyribonuclease Ksp632I; D015252:Deoxyribonucleases, Type II Site-Specific; C030986:pyrimidine