Distinct Classes of Yeast Promoters Revealed by Differential TAF Recruitment

Abstract

The transcription factor TFIID contains the TATA box binding protein (TBP) and multiple TBP-associated factors (TAFs). Here, the association of TFIID components with promoters that either are dependent on multiple TAFs (TAF _dep ) or have no apparent TAF requirement (TAF _ind ) is analyzed in yeast. At TAF _dep promoters, TAFs are present at levels comparable to that of TBP, whereas at TAF _ind promoters, TAFs are present at levels that approximate background. After inactivation of several general transcription factors, including TBP, TAFs are still recruited by activators to TAF _dep promoters. The results reveal two classes of promoters: at TAF _ind promoters, TBP is recruited in the apparent absence of TAFs, whereas at TAF _dep promoters, TAFs are co-recruited with TBP in a manner consistent with direct activator-TAF interactions.