R. Evans et al., Activator-mediated disruption of sequence-specific DNA contacts by the general transcription factor TFIIB, GENE DEV, 15(22), 2001, pp. 2945-2949
The transcription factor TFIIB plays a central role in preinitiation comple
x assembly, providing a bridge between promoter-bound TFIID and RNA Polymer
ase II. TFIIB possesses sequence-specific DNA-binding ability and interacts
with the TFIIB-recognition element (BRE), present in many promoters. Here
we show that the BRE suppresses the basal level of transcription elicited b
y a core promoter, which increases the amplitude of transcriptional stimula
tion in the presence of an activator protein. Further, we find that an acti
vator can disrupt the TFIIB-BRE interaction within a promoter-bound complex
. Our results reveal a novel function for activators in the modulation of c
ore promoter recognition by TFIIB.