Predicted to enable RNA polymerase II general transcription initiation factor activity and double-stranded DNA binding activity. Predicted to be involved in nucleotide-excision repair; phosphorylation of RNA polymerase II C-terminal domain; and transcription by RNA polymerase II. Predicted to be located in nuclear speck. Predicted to be part of core TFIIH complex portion of holo TFIIH complex and transcription factor TFIID complex. Orthologous to human GTF2H4 (general transcription factor IIH subunit 4). [provided by Alliance of Genome Resources, Apr 2022]