title: Homopurine/homopyrimidine sequences as potential regulatory elements in eukaryotic cells.
abstract: 1. Homopurine/homopyrimidine (PuPy) repetitive duplex sequences can form intramolecular triplexes (H-DNA) or intermolecular triplexes with a third strand in a sequence-specific manner. 2. Such sequences are present in natural genomes within 5'- and 3'-flanking sequences and coding regions of genes. Triplex DNA structures have been detected in vitro and in vivo and have been immunolocalized to chromosomes by triplex-specific monoclonal antibody approaches. 3. Intermolecular triplex formation represses gene expression at the transcriptional level and is also useful in genomic mapping, gene cloning, sequence-specific drug delivery, and selective modulation of gene expression.
authors.affiliation: Horticultural Sciences Department, University of Florida, Gainesville 32611.
authors.forename: G
authors.initials: G
authors.lastname: Lu
authors.forename: R J
authors.initials: RJ
authors.lastname: Ferl
mesh_terms: D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D005057:Eukaryotic Cells / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011685:Purine Nucleotides / Q000235:genetics*; D011742:Pyrimidine Nucleotides / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid
chemical_list: D011685:Purine Nucleotides; D011742:Pyrimidine Nucleotides; D004247:DNA