TFIIE is compiled of two subunits, alpha and beta. This family of proteins are the C terminal domain of the alpha subunit of the protein which is the largest subunit and contains several functional domains which are important for basal transcription and cell growth. The C terminal end of the protein binds directly to the amino-terminal PH domain of p62/Tfb1 (of IIH) which is involved in the recruitment of the general transcription factor IIH to the transcription preinitiation complex. P53 competes for the same binding site as TFIIE alpha which shows their structural similarity. Like p53, TFIIE alpha 336-439 can activate transcription in vivo [1].

1: p53 and TFIIEalpha share a common binding site on the Tfb1/p62 subunit of TFIIH. Di Lello P, Miller Jenkins LM, Mas C, Langlois C, Malitskaya E, Fradet-Turcotte A, Archambault J, Legault P, Omichinski JG; Proc Natl Acad Sci U S A. 2008;105:106-111. PMID:18160537