Partial characterization of the DNA repair protein complex, containing the ERCC1, ERCC4, ERCC11 and XPF correcting activities

Abstract The nucleotide excision repair (NER) protein ERCC1 is part of a functional complex, which harbors in addition the repair correctig activities of ERCC4, ERCC11 and human XPF. ERCC1 is not associated with a defect in any of the known human NER disorders: xeroderma pigmentosum, Cockayne's syndrome or trichothiodystrophy. Here we report the partial purification and characterization of the ERCC1 complex. Immunoprecipitation studies tentatively identified a subunit in the complex with an apparent MW of ∼ 120 kDa. The complex has affinity for DNA, but no clear preference for ss, ds or UV-damaged DNA substrates. The size of the entire complex determined by non-denaturing gradient gels (∼ 280 kDa) is considerably larger than previously found using size separation on glycerol gradients (∼ 120 kDa). Stable associations of the ERCC1 complex with other known repair factors (XPA, XPC, XPG and TFIIH complex) could not be detected.