General transcription factor IIH subunit 5 (GTF2H5)

General transcription factor IIH subunit 5 (GTF2H5), also known as TTDA or p8, is a small (71-amino acid) protein that is a subunit of the transcription/repair factor TFIIH complex. TFIIH is essential for both transcription initiation (by RNA polymerase II) and nucleotide excision repair, a critical DNA repair pathway. GTF2H5 is required for the stability of the multiprotein TFIIH complex and helps promote the opening of DNA at sites of transcription or damage, allowing further processing for transcription or repair. In humans, mutations in GTF2H5 result in a photosensitive form of trichothiodystrophy, a rare genetic disorder characterized by brittle hair, developmental delay, and increased sensitivity to UV light caused by impaired DNA repair capacity[1][2][3][7]. There are no known drugs directly targeting this subunit, but the TFIIH complex is a fundamental node in genomic regulation and cell viability.

Other names

TTDAp8TTD-AC6orf175TFB5FLJ30544bA120J8.2DNA repair syndrome trichothiodystrophy group Ageneral transcription factor IIH polypeptide 5TFB5 orthologTFIIH basal transcription factor complex TTD-A subunitTFIIH subunit p8