Transcription initiation factors (TFII) are proteins which enable RNA polymerase II to bind to the DNA template in order to start the transcription process. TFIID recognizes the promoter sequence on the DNA while TFIIB bridges between TFIID and RNA polymerase II. TFIIA is one of several TFs which are required for transcription. TFIIA aids in binding the TATA-binding protein (TBP) to the TATA box containing sequence of the DNA.
3D structures of transcription initiation factors
TFIIA
1ytf – TFIIA + TBP + DNA – yeast
TFIIB
1pft – TFIIB N terminal – Pyrococcus furiosus – NMR
1tfb – hTFIIB – human - NMR
1vol, 1c9b – hTFIIB + TBP + DNA
1ais, 1d3u - TFIIB C terminal + TBP + DNA – Pyrococcus woesei
TFIID
1bh8 – hTFIID
1tba – TFIID – Drosophila melanogaster - NMR
1bh9 – hTFIID + PCMBS
1qn3, 1qn4, 1qn5, 1qn6, 1qn7, 1qn8, 1qn9, 1qna, 1qnb, 1qnc – TFIID + DNA – Arabidopsis thaliana
