Transcription initiation factor IIF, alpha subunit, N-terminal region of RAP74. Subunit of transcription initiation complex involved in initiation, elongation and promoter escape.Tetramer of 2 alpha and 2 beta TFIIF subunits interacts directly with RNA polymerase II. TFIIF inhibits non-specific transcription initiation by PolII and recruits the polymerase to the preinitiation complex on promoter DNA for site-specific transcription initiation. The PolII/TFIIF-complex attaches through direct interactions of TFIIF with promoter DNA, TFIIB and the TAF250 subunit of TFIID, and provides scaffolding for addition of TFIIE and TFIIH. Together with TFIIE, TFIIF participates in DNA strand separation (open complex formation). N-terminal domains of RAP30 and RAP74 co-fold to form a single core structure, a triple barrel heterodimer, and has pseudo-2-fold symmetry.
Jiyao W et al.(2023). "The conserved domain database in 2023.",