HIGHLY CONSERVED CORE DOMAIN AND UNIQUE N-TERMINUS WITH PRESUMPTIVE REGULATORY MOTIFS IN A HUMAN TATA FACTOR (TFIID)

THE factor TFIID is one of several general factors that are necessary and sufficient for transcription initiation by mammalian RNA polymerase II1,2. Stable interactions with the common TATA element3,4 lead both to template commitment and to the assembly of the other general factors into a functional preinitiation complex5,6. Consistent with its key role in the promoter activation pathway, human TFIID also seems to be a target for some regulatory factors, as evidenced both by physical3,7,8 and functionall9-12 studies of interactions between these components. The evolutionary conservation of functional properties13,14 led to the purification and cloning of yeast TFIID15-19, the identification of presumptive structural motifs15,19, and direct structure-function studies20. Here we report the cloning of a complementary DNA encoding a functional human TFIID. This reveals an evolutionary conserved core which corresponds precisely to the 180-residue DNA binding/activation domain determined20 for yeast TFIID, a near absolute conservation of component structural motifs (direct repeats, central basic core/lysine repeat, and sigma homology), providing further support for their functional importance, and a unique N-terminal structure that suggests involvement in species-specific regulatory factor interactions. © 1990 Nature Publishing Group.