General transcription and DNA repair factor IIH helicase subunit XPD/RAD3

UniProtKB accession:  P06839

Grouped By:  Matching UniProtKB accession

UniProtKB description:  ATP-dependent 5'-3' DNA helicase (PubMed:25775526, PubMed:2827162). 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. The ATP-dependent helicase activity of XPD/RAD3 is required for DNA opening. 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. XPD/RAD3 acts by forming a bridge between TFIIK and the core-TFIIH complex. Involved in the maintenance of the fidelity of DNA replication. Has single-stranded DNA-dependent ATPase activity (PubMed:2957691). 5'-3' DNA helicase activity requires ATP (dATP partially substitutes), will unwind over 800 bp dsDNA (PubMed:2827162). Able to unwind an RNA:DNA hybrid (PubMed:1719538).