Transcription factor II H

Two other TFIIH subunits, CDK7 and cyclin H, phosphorylate serine amino acids on the RNA polymerase II C-terminal domain and possibly other proteins involved in the cell cycle.

Next to a vital function in transcription initiation, TFIIH is also involved in nucleotide excision repair.

[8][9] Purified TFIIH has role in stopping further RNA synthesis by activating the cyclic peptide α-amanitin.

Mutation in genes ERCC3 (XPB), ERCC2 (XPD) or GTF2H5 (TTDA) cause trichothiodystrophy, a condition characterized by photosensitivity, ichthyosis, brittle hair and nails, intellectual impairment, decreased fertility and/or short stature.

[12] TFIIH participates in nucleotide excision repair (NER) by opening the DNA double helix after damage is initially recognized.

Potent, bioactive natural products like triptolide that inhibit mammalian transcription via inhibition of the XPB subunit of the general transcription factor TFIIH has been recently reported as a glucose conjugate for targeting hypoxic cancer cells with increased glucose transporter expression.