Yeast TFIIE. Cloning, expression, and homology to vertebrate proteins.

Genes encoding both the 66- and the 43-kDa subunits of yeast RNA polymerase II initiation factor a, designated TFA1 and TFA2, have been isolated. Both genes are essential for cell viability. The bacterially expressed gene products could replace factor a in transcription in vitro, and both recombinant subunits were required for activity. The deduced amino acid sequences of the TFA1 and TFA2 gene products were homologous to those of the large and small subunits of human TFIIE, respectively, identifying factor a as the yeast homolog of TFIIE.