SELECTIVE USE OF TBP AND TFIIB REVEALED BY A TATA-TBP-TFIIB ARRAY WITH ALTERED SPECIFICITY

Interaction between the TATA box-binding protein TBP and TFIIB is crit ical for transcription in vitro. An altered-specificity TBP-TFIIB inte raction was rationally designed and linked in sequence to an altered-s pecificity TATA box-TBP interaction to study how TBP and TFIIB functio n together to support transcription in human cells. The activity of th is altered-specificity TATA-TBP-TFIIB array demonstrated that many act ivators use the known TBP-TFIIB interaction to stimulate transcription . One activator, however, derived from a glutamine-rich activation dom ain of Sp1, activated transcription independently of this interaction. These results reveal that selectivity in activator function in vivo c an be achieved through differential use of TBP and TFIIB.