p52 Mediates XPB function within the transcription/repair factor TFIIH.
To further our understanding of the transcription/DNA repair factor TFIIH, we investigated the role of its p52 subunit in TFIIH function. Using a completely reconstituted in vitro transcription or nucleotide excision repair (NER) system, we show that deletion of the C-terminal region of p52 results in a dramatic reduction of TFIIH NER and transcription activities. This mutation prevents promoter opening and has no effect on the other enzymatic activities of TFIIH. Moreover, we demonstrate that intact p52 is needed to anchor the XPB helicase within TFIIH, providing an explanation for the transcription and NER defects observed with the mutant p52. We show that these two subunits physically interact and map domains involved in the interface. Taken together, our results show that the p52/Tfb2 subunit of TFIIH regulates the function of XPB through pair-wise interactions as described previously for p44 and XPD.
Jawhari
Anass
A
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/Universite Louis Pasteur, B. P.10142, 67404 Illkirch Cedex, France.
Lainé
Jean-Philippe
JP
Dubaele
Sandy
S
Lamour
Valérie
V
Poterszman
Arnaud
A
Coin
Frédéric
F
Moras
Dino
D
Egly
Jean-Marc
JM
D048868:Adaptor Proteins, Signal Transducing; D001483:Base Sequence; D001665:Binding Sites; D004265:DNA Helicases; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D015534:Trans-Activators / Q000378:metabolism*; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C504649:PSIP1 protein, human; D011994:Recombinant Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C072022:XPBC-ERCC-3 protein; D051758:Transcription Factor TFIIH; D004265:DNA Helicases