title: The molecular weights of yeast ribosomal precursor RNAs.
abstract: The molecular weights of the predominant rRNA precursors as well as those of 26-S and 17-S mature rRNA from Saccharomyces carlsbergensis were determined by polyacrylamide gel electrophoresis in the presence of formamide. Mature 26-S + 5.8-S rRNA was found to have a molecular weight of 1.24 X 10(6) while their immediate precursor, 29-S RNA, had a molecular weight of 1.52 X 10(6). Values of 0.70 X 10(6) and 0.82 X 10(6) were obtained  for the molecular weights of mature 17-S rRNA and its 18-S precursor. Finally the 37-S precursor, common to both 29-S and 18-S RNA, was found to have a molecular weight of 2.80 X 10(6). Each precursor rRNA, therefore, contains extra sequences not found at the next stage of maturation.
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D012335:RNA, Ribosomal / Q000096:biosynthesis; D012440:Saccharomyces / Q000378:metabolism*
chemical_list: D012335:RNA, Ribosomal