A wide variety of DNA sequences can functionally replace a yeast TATA element for transcriptional activation

We created a library of DNA molecules in which the required TATA element of a yeast gal-his3 promoter is replaced by random-sequence oligomers averaging 16 bp in length. Surprisingly, 1% of such random sequences functionally replace the native yeast TATA element. In many cases, sequences completely unrelated to the consensus TATA element (TATAAA) stimulate transcription with equal or increased efficiency. Transcription mediated by these synthetic elements requires GAL4 and is initiated from normal his3 initiation sites, suggesting that it occurs by a mechanism indistinguishable from that involving wild-type TATA elements. Many, but not all, of these elements act as substrates for yeast TFIID in reconstituted transcription reactions in vitro. These observations indicate that yeast TFIID can stimulate transcription from TATA elements whose sequences differ from the consensus, and they suggest the possibility of alternative factors that may provide a related function for transcriptional activation.