The Rpb9 subunit of RNA polymerase II binds transcription factor TFIIE and interferes with the SAGA and elongator histone acetyltransferases.
Rpb9 is a small subunit of yeast RNA polymerase II participating in elongation and formed of two conserved zinc domains. rpb9 mutants are viable, with a strong sensitivity to nucleotide-depleting drugs. Deleting the C-terminal domain down to the first 57 amino acids has no detectable growth defect. Thus, the critical part of Rpb9 is limited to a N-terminal half that contacts the lobe of the second largest subunit (Rpb2) and forms a beta-addition motif with the "jaw" of the largest subunit (Rpb1). Rpb9 has homology to the TFIIS elongation factor, but mutants inactivated for both proteins are indistinguishable from rpb9 single mutants. In contrast, rpb9 mutants are lethal in cells lacking the histone acetyltransferase activity of the RNA polymerase II Elongator and SAGA factors. In a two-hybrid test, Rpb9 physically interacts with Tfa1, the largest subunit of TFIIE. The interacting fragment, comprising amino acids 62-164 of Tfa1, belongs to a conserved zinc motif. Tfa1 is immunoprecipitated by RNA polymerase II. This co-purification is strongly reduced in rpb9-Delta, suggesting that Rpb9 contributes to the recruitment of TFIIE on RNA polymerase II.
Van Mullem
Vincent
V
Laboratoire de Génétique Moléculaire, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgique.
Wery
Maxime
M
Werner
Michel
M
Vandenhaute
Jean
J
Thuriaux
Pierre
P
D000123:Acetyltransferases / Q000378:metabolism; D000595:Amino Acid Sequence; D051548:Histone Acetyltransferases; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*; D019473:Transcription Factors, TFII; D020798:Two-Hybrid System Techniques
D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C066644:transcription factor TFIIE; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; D012319:RNA Polymerase II