CLONING AND CHARACTERIZATION OF P52, THE 5TH SUBUNIT OF THE CORE OF THE TRANSCRIPTION DNA REPAIR FACTOR TFIIH/

TFIIH is a multiprotein factor involved in transcription and DNA repai r and is implicated in DNA repair/ transcription deficiency disorders such as xeroderma pigmentosum. Cockayne syndrome and trichothiodystrop hy. Eight out of the nine genes encoding the subunits forming TFIIH ha ve already been cloned. We report here the identification, cDNA clonin g and gene structure of the 52 kDa polypeptide and its homology with t he yeast counterpart TFB2. This protein, along with p89/XPB, p62, p44 and p34, forms the core of TFIIH. Moreover, using in vitro reconstitut ed transcription and nucleotide excision repair (NER) assays and micro injection experiments, we demonstrate that p52 is directly involved in both transcription and DNA repair mechanisms in vitro and in vivo.