Functional Analysis of TFIID Components

Excerpt

Transcription of eukaryotic structural genes requiresthe assembly of RNA polymerase II and the general transcription factors (GTFs) TFIIA, TFIIB, TFIID, TFIIE,TFIIF, and TFIIH on the promoter to form a preinitiationcomplex (PIC). Of these GTFs, TFIID is the major sequence-specific DNA-binding component; the otherGTFs enter the PIC primarily through protein-protein interactions. TFIID is composed of the TATA-box-bindingprotein (TBP) and multiple TBP-associated factors(TAF_IIs). Initial in vitro biochemical characterizationsled to the proposal that TAFs are obligatory coactivatorsessential for a response to an activator. Subsequent invivo studies demonstrated, in contrast, that TAF_IIs are notgeneral coactivators but rather are highly promoter selective. In this paper, we review studies in which the function of TFIID components has been analyzed, and we discuss evidence pointing to a close relationship betweenTAF_IIs and the core promoter...