Of these , the XPB and XPD genes encode proteins that are subunits of a general transcription factor , TFIIH , involved in both nucleotide excision repair ( NER ) and initiation of mRNA transcription by RNA polymerase II .
of these , the xpb and xpd genes encode proteins that are subunits of a general transcription factor , tfiih , involved in both nucleotide excision repair ( ner ) and initiation of mrna transcription by rna polymerase ii .
O O O O O O O O O O O O O O O B-protein_molecule I-protein_molecule I-protein_molecule O B-protein_molecule O O O O B-other_name I-other_name I-other_name O B-other_name O O O O B-other_name I-other_name O B-protein_complex I-protein_complex I-protein_complex O