Interference of papillomavirus E6 protein with single-strand break repair by interaction with XRCC1.

XRCC1 protein is required for the repair of DNA single-strand breaks and genetic stability, and is essential for viability in mammals. XRCC1 functions as a scaffold protein by interacting and modulating polypeptide components of the single-strand break repair machinery, including AP endonuclease-1, DNA ligase IIIalpha, poly (ADP-ribose) polymerase, DNA polymerase beta and human polynucleotide kinase. We show here that the E6 protein of human papillomavirus type 1, 8 and 16 directly binds XRCC1.