title: A novel collection of accessory factors associated with yeast RNA polymerase II.
abstract: A relatively simple subset of general transcription factors is sufficient for transcript initiation by RNA polymerase II. However, a recently identified "holoenzyme" contains additional accessory proteins required for mediating signals from some activators (Y-J. Kim et al., 1994, Cell 77, 599-608; A. Koleske and R. Young, 1994, Nature 368, 466-469). By immobilizing RNA polymerase II and associated proteins (RAPs) from a transcriptionally active yeast extract, we have identified a novel collection of proteins distinct from those found in the holoenzyme. The eluted RAP fraction did not contain the holoenzyme components Srb2,4,5 + 6p, Gal11p, or Sug1p, but did include the known transcription factors TFIIB and TFIIS and the three subunits of yeast TFIIF (Ssu71p/Tfg1p, Tfg2p, and Anc1p/Tfg3p). Also isolated as RAPs are two proteins (Cdc73p and Paf1p) with interesting connections to gene expression. Mutations in CDC73 and PAF1 affect cell growth and the abundance of transcripts from a subset of yeast genes (X. Shi et al., Mol. Cell. Biol., 1996 16, 669-676). The RAP fraction may therefore define one or more functional forms of RNA polymerase II distinct from the activator-mediating holoenzyme.
authors.affiliation: Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, Denver, Colorado, 80262, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Wade
authors.forename: W
authors.initials: W
authors.lastname: Werel
authors.forename: R C
authors.initials: RC
authors.lastname: Fentzke
authors.forename: N E
authors.initials: NE
authors.lastname: Thompson
authors.forename: J F
authors.initials: JF
authors.lastname: Leykam
authors.forename: R R
authors.initials: RR
authors.lastname: Burgess
authors.forename: J A
authors.initials: JA
authors.lastname: Jaehning
authors.forename: Z F
authors.initials: ZF
authors.lastname: Burton
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D002846:Chromatography, Affinity; D005656:Fungal Proteins / Q000302:isolation & purification; D005800:Genes, Fungal / Q000235:genetics; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification; D012319:RNA Polymerase II / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017421:Sequence Analysis; D014157:Transcription Factors / Q000737:chemistry / Q000302:isolation & purification*; D015533:Transcriptional Activation / Q000235:genetics; D015003:Yeasts / Q000737:chemistry / Q000201:enzymology*
chemical_list: D000911:Antibodies, Monoclonal; D005656:Fungal Proteins; D009687:Nuclear Proteins; C097698:PAF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012319:RNA Polymerase II