<p>Initiation of eukaryotic mRNA transcription requires melting of promoter DNA with the help of the general transcription factors TFIIE and TFIIH. In higher eukaryotes, the general transcription factor TFIIE consists of two subunits: the large alpha subunit (<db_xref db="INTERPRO" dbkey="IPR002853"/>) and the small beta (<db_xref db="INTERPRO" dbkey="IPR003166"/>). TFIIE beta has been found to bind to the region where the promoter starts to open to be single-stranded upon transcription initiation by RNA polymerase II. The approximately 120-residue central core domain of TFIIE beta plays a role in double-stranded DNA binding of TFIIE [<cite idref="PUB00006521"/>].</p><p>The TFIIE beta central core DNA-binding domain consists of three helices with a beta hairpin at the C terminus, resembling the winged helix proteins. It shows a novel double-stranded DNA-binding activity where the DNA-binding surface locates on the opposite side to the previously reported winged helix motif by forming a positively charged furrow [<cite idref="PUB00006521"/>].</p><p> Archaea contain a TFIIE homolog, called TFE, which corresponds to the N-terminal half of TFIIEalpha. It appears that archaeal TFE corresponds to the minimal essential region of eukaryotic TFIIEalpha. In archaea TFE contains an N-terminal, weakly conserved, helix-turn-helix (HTH) motif within a leucine-rich region and a C-terminal zinc ribbon [<cite idref="PUB00043742"/>, <cite idref="PUB00043743"/>, <cite idref="PUB00043744"/>]. It has been proposed that the TFE/IIEalpha-type HTH domain acts as a bridging factor or adapter between the TATA box-binding protein, the polymerase, and possibly promoter DNA [<cite idref="PUB00043809"/>].</p>This entry represents archaeal TFE.