Altered promoter binding of the TATA box-binding factor induced by the transcriptional activation domain of VP16 and suppressed by TFIIA.
The acidic transcriptional activation domain of the Herpes simplex virus protein VP16 has been shown to bind directly to both the TATA box-binding factor TBP and the general initiation factor TFIIB. Using DNase I footprinting assays, we have shown here that the VP16 activation domain qualitatively alters binding of Saccharomyces cerevisiae TBP to a TATA sequence in DNA. The effect of VP16 on promoter binding by TBP was reduced by mutations in VP16 known to reduce transactivation and could not be overcome by increasing the amount of TBP used in the footprinting assays. However, the association of yeast TFIIA with TBP on the promoter reversed the VP16-mediated effect and restored normal binding of TBP to the promoter. We suggest that VP16 induces a conformational change in TBP which alters its binding to promoter DNA, and that this effect of VP16 is suppressed by TFIIA.
Liljelund
P
P
Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
Ingles
C J
CJ
Greenblatt
J
J
D001667:Binding, Competitive; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism*; D066298:In Vitro Techniques; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D017405:Herpes Simplex Virus Protein Vmw65; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D014157:Transcription Factors