Contributes to damaged DNA binding activity. Involved in nucleotide-excision repair and transcription by RNA polymerase II. Predicted to be located in chromosome and nucleus. Predicted to be part of transcription factor TFIIH core complex and transcription factor TFIIH holo complex. Expressed widely. Used to study trichothiodystrophy. Human ortholog(s) of this gene implicated in photosensitive trichothiodystrophy 3. Is an ortholog of human GTF2H5 (general transcription factor IIH subunit 5).