Molecular mass of RNA polymerase II holoenzyme

Range ~4 MDa
Organism Eukaryotes
Reference Jackson DA, Pombo A, Iborra F. The balance sheet for transcription: an analysis of nuclear RNA metabolism in mammalian cells. FASEB J. 2000 Feb14(2):242-54. p.242 right column 2nd paragraphPubMed ID10657981
Primary Source See refs in - link
Comments "Three different RNA polymerase (pol) complexes perform RNA synthesis in the nuclei of mammalian cells (11, 12). In most cells, RNA polymerase II (pol II) is the major activity, transcribing all protein-coding genes to generate patterns of gene expression that determine cell type. Synthesis is performed by an ~4 MDa holoenzyme containing the pol II core enzyme and other activities required during RNA synthesis and processing (primary sources). RNA polymerase I (pol I) is dedicated to the synthesis of the repeated ribosomal RNA (rRNA) genes, within specialized nuclear sites—nucleoli—and RNA polymerase III (pol III), a minor nucleoplasmic activity, transcribes transfer RNA (tRNA) and 5S rRNA genes. Small nuclear RNA (snRNA) and small nucleolar RNA (snoRNA) genes encode structural RNAs needed for RNA processing some are transcribed by pol II and others by pol III."
Entered by Uri M
ID 111152