Transcription factor b (TFIIH) is required during nucleotide-excision repair in yeast.
Nucleotide-excision repair (NER) is an important cellular defence mechanism against mutagenesis and carcinogenesis. The essential yeast genes RAD3 (ref. 2) and SSL2 (RAD25), homologues of the human xeroderma pigmentosum genes XPD and XPB respectively, have been implicated in NER in yeast. The products of these genes are also subunits of (Rad3 protein) or associate with (Ssl2 protein) purified yeast RNA polymerase II transcription initiation factor b, the counterpart of human TFIIH. Rad3 and Ssl2 proteins may participate directly in NER. Alternatively, they may function exclusively as transcription factors that support NER by influencing the expression of other NER genes. Here we show that defective NER in rad3 mutant extracts can be specifically complemented by purified transcription factor b. Similarly, defective NER in ssl2 mutant extracts is corrected by purified factor b/Ssl2 complex. These results support a direct role of factor b during NER in yeast. Hence, factor b (TFIIH) has a dual role in transcription and NER.
Wang
Z
Z
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235.
Svejstrup
J Q
JQ
Feaver
W J
WJ
Wu
X
X
Kornberg
R D
RD
Friedberg
E C
EC
D000099:Acetoxyacetylaminofluorene; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004271:DNA, Fungal / Q000096:biosynthesis / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic
D004271:DNA, Fungal; D005656:Fungal Proteins; C489575:SSL2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C490039:TAF6 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D051758:Transcription Factor TFIIH; D000099:Acetoxyacetylaminofluorene; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases