p53 modulation of TFIIH–associated nucleotide excision repair activity

p53 has pleiotropic functions including control of genomic plasticity and integrity. Here we report that p53 can bind to several transcription factor IIH–associated factors, including transcription–repair factors, XPD (Rad3) and XPB, as well as CSB involved in strand–specific DNA repair, via its C–terminal domain. We also found that wild–type, but not Arg273His mutant p53 inhibits XPD (Rad3) and XPB DNA helicase activities. Moreover, repair of UV–induced dimers is slower in Li–Fraumeni syndrome cells (heterozygote p53 mutant) than in normal human cells. Our findings indicate that p53 may play a direct role in modulating nucleotide excision repair pathways.