Characterization of a nucleolar residue fraction that specifically transcribes preribosomal RNA.
Treatment of isolated nucleoli with Sarkosyl (2%) dissociated 99.5% of the proteins. The residual DNA-protein complex contained the endogenous transcriptional activity which had a high fidelity of RNA synthesis. Electron microscopic analysis of this residue fraction showed the presence of 150-200A diameter protein globules present along the length of some of the DNA fibers. SDS-polyacrylamide gel electrophoretic analysis of the proteins of the complex indicated that the subunits of purified RNA polymerase I were only a minor component of this complex. Associated with the complex were the U3 and 5S RNA.
D000818:Animals; D002460:Cell Line; D002466:Cell Nucleolus / Q000032:analysis* / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D008114:Liver Neoplasms, Experimental; D009694:Nucleic Acid Precursors / Q000235:genetics*; D011506:Proteins / Q000032:analysis*; D012318:RNA Polymerase I / Q000032:analysis; D012335:RNA, Ribosomal / Q000235:genetics*; D051381:Rats; D014158:Transcription, Genetic
D003902:Detergents; D009694:Nucleic Acid Precursors; D011506:Proteins; D012335:RNA, Ribosomal; D012318:RNA Polymerase I