The Spt components of SAGA facilitate TBP binding to a promoter at a post-activator-binding step in vivo.
The SAGA complex of Saccharomyces cerevisiae is required for the transcription of many RNA polymerase II-dependent genes. Previous studies have demonstrated that SAGA possesses histone acetyltransferase activity, catalyzed by the SAGA component Gcn5. However, the transcription of many genes, although SAGA dependent, is Gcn5 independent, suggesting the existence of distinct SAGA activities. We have studied the in vivo role of two other SAGA components, Spt3 and Spt20, at the well-characterized GAL1 promoter. Our results demonstrate that both Spt3 and Spt20 are required for the binding of TATA-binding protein but not of the activator Gal4 and that this role is Gcn5 independent. These results suggest a coactivator role for Spt3 and Spt20 in the recruitment of TBP.
Dudley
A M
AM
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Rougeulle
C
C
Winston
F
F
D000107:Acetylation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D004790:Enzyme Induction; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D005686:Galactokinase / Q000096:biosynthesis / Q000235:genetics*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D051548:Histone Acetyltransferases; D046911:Macromolecular Substances; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D014158:Transcription, Genetic; D000099224:p300-CBP-Associated Factor
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D005686:Galactokinase; D051548:Histone Acetyltransferases; D046911:Macromolecular Substances; D011494:Protein Kinases; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; C052130:GAL4 protein, S cerevisiae; C099690:SPT20 protein, S cerevisiae; C075582:SPT3 protein, S cerevisiae; C501392:GCN5 protein, S cerevisiae; D000099224:p300-CBP-Associated Factor