General Transcription Factor IIF, Polypeptide 2 (GTF2F2)

The RNA polymerase II transcription factor TFIIF is a heterodimer with 2 subunits: one, referred to as RAP74, of approximately 70 kD and the other, known as RAP30 or GTF2F2, of 30 kD. TFIIF affects RNA polymerase II activity both during the initiation and elongation stages of RNA transcription. Sopta et al. (1989) purified RAP30 from HeLa cells and raised an antibody to the protein, which was then used to screen an expression cDNA library from the promyelocytic leukemia cell line, HL60. The predicted protein was 234 amino acids in length. Subsequently, Horikoshi et al. (1991) corrected the RAP30 cDNA sequence to show that the predicted protein is actually 249 amino acids. TFIIF appears to assist TFIIB in recruiting RNA polymerase II into a preinitiation complex.