Conserved sequence motifs in the small subunit of human general transcription factor TFIIE

A GENERAL initiation factor, TFIIE, is essential for transcription initiation by RNA polymerase II in conjunction with other general factors^1,2. TFIIE is a heterotetramer containing two subunits of relative molecular mass 57,000 (TFIIE-α) and two of 34,000 (TFIIE-β)^3,4. TFIIE-β is required in conjunction with TFIIE-α for transcription initiation. Here we report the cloning and expression of a complementary DNA encoding a functional human TFIIE-β. Recombinant TFIIE-β could replace the natural TFIIE-β for transcription in conjunction with TFIIE-α. Amino-acid sequence comparisons reveal regions with sequence similarities to: subregion ³ of bacterial factors⁶; a region of RAP30 (the small subunit of TFIIF) with sequence similarity to a a factor subregion implicated in binding to RNA polymerase⁷; and a portion of the basic region-helix-loop-helix motif found in several enhancer-binding proteins^8,10. These potential homologies have implications for the role of TFIIE in preinitiation complex assembly and function.