title: Characterization of double-stranded ribonucleic acid sequences present in the initial transcription products of rat liver chromatin.
abstract: At low ionic strength and with a low exogenous RNA polymerase/DNA ratio, rat liver chromatin directs the synthesis in vitro of RNA sequences rich in double-stranded segments. All the transcripts contain at least one double-stranded sequence. Most of the double-stranded segments are formed by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. They are heterogeneous in size, 35-45% of them being more than 80 nucleotides long. They contain 61-64% G+C, whether synthesized by rat liver RNA polymerase (form B) or Escherichia coli RNA polymerase. The largest double-stranded sequences are found in the largest transcripts, and are the most thermostable. The fidelity of base-matching is better in double-stranded transcripts synthesized on rat liver chromatin by homologous polymerase than in those synthesized on it by a bacterial polymerase, or in those synthesized by either of the two polymerases on pure DNA.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases; D006358:Hot Temperature; D008099:Liver / Q000378:metabolism*; D009691:Nucleic Acid Denaturation; D012313:RNA / Q000032:analysis*; D051381:Rats; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D012313:RNA; D012321:DNA-Directed RNA Polymerases