title: Human ribosomal DNA: conserved sequence elements in a 4.3-kb region downstream from the transcription unit.
abstract: The sequence of 4366 bp of nontranscribed spacer (NTS) human ribosomal DNA (rDNA) located downstream from the 3' end of the transcription unit has been determined. The NTS rDNA is rich in pyrimidine nucleotides (31% T and 30% C) that tend to occur on the coding strand in runs of simple sequence repeats. Other highly repetitive sequence elements are also represented, including tracts of (dA-dC)26 and (dG-dT)29 on the coding strand downstream from the putative termination of transcription. Still farther downstream, two Alu repeat sequences are found. Such sequences are also found in rat DNA at comparable locations, consistent with the possibility of a comparable functional role.
authors.affiliation: Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.
authors.forename: K R
authors.initials: KR
authors.lastname: Dickson
authors.forename: D C
authors.initials: DC
authors.lastname: Braaten
authors.forename: D
authors.initials: D
authors.lastname: Schlessinger
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D004275:DNA, Ribosomal / Q000235:genetics*; D005809:Genes, Regulator; D006801:Humans; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D014158:Transcription, Genetic
chemical_list: D004275:DNA, Ribosomal