TFB5, General transcription and DNA repair factor IIH subunit TFB5
Also Known as
Component of the general transcription and DNA repair factor IIH (TFIIH) core complex, which is involved in general and transcription-coupled nucleotide excision repair (NER) of damaged DNA and, when complexed to TFIIK, in RNA transcription by RNA polymerase II. In NER, TFIIH acts by opening DNA around the lesion to allow the excision of the damaged oligonucleotide and its replacement by a new DNA fragment. In transcription, TFIIH has an essential role in transcription initiation. When the pre-initiation complex (PIC) has been established, TFIIH is required for promoter opening and promoter escape. Phosphorylation of the C-terminal tail (CTD) of the largest subunit of RNA polymerase II by the kinase module TFIIK controls the initiation of transcription. TFB5 is required for stable recruitment of TFIIH to a promoter, but not for stability of TFIIH subunits. Component of the 7-subunit TFIIH core complex composed of XPB/SSL2, XPD/RAD3, SSL1, TFB1, TFB2, TFB4 and TFB5, which is active in NER. The core complex associates with the 3-subunit CTD-kinase module TFIIK composed of CCL1, KIN28 and TFB3 to form the 10-subunit holoenzyme (holo-TFIIH) active in transcription (PubMed:15220919). Interacts with TFB2 (PubMed:19172752).