title: The primary transcript of the ribosomal repeating unit in yeast.
abstract: Endgroup analysis of 37S ribosomal precursor RNA from Saccharomyces carlsbergensis has revealed that the major 5' endgroup is ppA-Up, with a molar yield of 0.8. This shows that most, if not all, 37S RNA molecules have preserved a transcriptional initiation sequence. Analysis of the 3' terminus of 37S RNA has shown the presence of a uridine rich oligonucleotide, tentatively identified as U6-8-A-NOH. This long stretch of uridines at the 3' end of 37S RNA may represent a transcriptional termination site. The two sets of data on the terminal sequences suggest that 37S ribosomal precursor RNA, if not already spliced, is a primary transcription product. Since the 3' terminus of 26S rRNA, U-U-U-G-UOH., appears to be clearly different from the 3' end of 37S RNA, we conclude that 37S ribosomal precursor RNA contains additional nucleotides 3'-distal to the 26S rRNA sequence.
mesh_terms: D001483:Base Sequence; D009843:Oligoribonucleotides / Q000032:analysis; D012335:RNA, Ribosomal / Q000096:biosynthesis / Q000302:isolation & purification; D006163:Ribonuclease T1; D012260:Ribonucleases; D012270:Ribosomes / Q000378:metabolism*; D012440:Saccharomyces / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D009843:Oligoribonucleotides; D012335:RNA, Ribosomal; D012260:Ribonucleases; D006163:Ribonuclease T1