General Transcription Factors

Abstract As described in Chapter 1, formation of the transcription initiation complex is required for Pol II transcription of protein-coding genes. This complex contains, in addition to the multiple subunits of Pol II, a set of general transcription factors that includes TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH (Table 14.1). These factors are involved in DNA-protein interactions (TFIID only); protein-protein interactions with Pol II, DNA binding transcriptional activators, and activator-bound coactivators; and enzymatic activities (DNA-dependent ATPase, DNA helicase, and protein kinase). In addition, TFIIH appears to play an essential role in both Pol II transcription and DNA repair processes (reviewed by Drapkin et al., 1994). (A complete description of DNA repair is beyond the scope of this book and interested readers should consult an authoritative text by Friedberg et al.[1995].) Among the many genes that encode components of the transcription initiation complex, germline mutations affecting only subunits of TFIIH have been identified as being responsible for hereditable human disorders.