J. Kim et al., A NEGATIVE COFACTOR CONTAINING DR1 P19 MODULATES TRANSCRIPTION WITH TFIIA IN A PROMOTER-SPECIFIC FASHION/, The Journal of biological chemistry, 271(31), 1996, pp. 18405-18412
An activity that modulated the relative levels of transcription from t
he adenovirus major late promoter (MLP), and the immunoglobulin heavy
chain mu promoter (mu) was purified as a 90-kDa factor, This factor is
suggested to be a heterotetramer of two subunits: a 20-kDa polypeptid
e identical to the previously described Dr1/p19 and a novel 30-kDa pol
ypeptide. The Dr1/p19 protein has been characterized as a repressor of
transcription, and the 30-kDa protein is related to a recently identi
fied yeast gene proposed to encode a repressor of transcription, The 9
0-kDa factor forms a complex with TATA-binding protein on DNA and at h
igh concentrations of both factors protects over a 150-base pair regio
n around the promoter from DNase I cleavage, The conformation of this
complex as assayed by footprinting analysis is altered by the transcri
ption factor TFIIA on the MLP but not on the mu promoter. Similarly, T
FIIA reverses the repression of transcription by the 90-kDa factor on
the MLP but not on the mu promoter, Thus, the interactions of TATA-bin
ding protein, TFIIA, and the 90-kDa factor are promoter-specific.