A novel collection of accessory factors associated with yeast RNA polymerase II.
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.
Wade
P A
PA
Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, Denver, Colorado, 80262, USA.
Werel
W
W
Fentzke
R C
RC
Thompson
N E
NE
Leykam
J F
JF
Burgess
R R
RR
Jaehning
J A
JA
Burton
Z F
ZF
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*
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