Several protein members of the BRCA1-associated genome surveillance complex (BASC) associate with RNA polymerase II and play a role in transcription.
The transcription factor TFIIH is involved in transcription initiation and DNA repair. MAT1 (for ménage à trois-1) is involved in the assembly of the CAK complex. CAK is a multisubunit protein that includes CDK7, cyclin H (CCNH), and MAT1. CAK is an essential component of the transcription factor TFIIH that is involved in transcription initiation and DNA repair.
The nucleotide excision repair (NER) pathway is a mechanism to repair damage to DNA. ERCC2 is involved in transcription-coupled NER and is an integral member of the basal transcription factor BTF2/TFIIH complex. ERCC3 is an ATP-dependent DNA helicase that functions in NER. It also is a subunit of basal transcription factor 2 (TFIIH) and, thus, functions in class II transcription. XPG (ERCC5) forms a stable complex with TFIIH, which is active in transcription and NER. ERCC6 encodes a DNA-binding protein that is important in transcription-coupled excision repair. ERCC8 interacts with Cockayne syndrome type B (CSB) protein, with p44 (GTF2H2), a subunit of the RNA polymerase II transcription factor IIH, and ERCC6. It is involved in transcription-coupled excision repair.
Higher error ratios in transcription by RNA polymerase II are observed in the presence of Mn compared to Mg.