An affinity of human replication protein A for ultraviolet-damaged DNA: Implications for damage recognition in nucleotide excision repair

John L. Burns, Sami N. Guzder, Patrick Sung, Satya Prakash, Louise Prakash

Research output: Contribution to journalArticle

108 Scopus citations


Replication protein A (RPA), a heterotrimeric protein of 70-, 32-, and 14-kDa subunits, is an essential factor for DNA replication. Biochemical studies with human and yeast RPA have indicated that it is a DNA-binding protein that has higher affinity for single-stranded DNA. Interestingly, in vitro nucleotide excision repair studies with purified protein components have shown an absolute requirement for RPA in the incision of UV-damaged DNA. Here we use a mobility shift assay to demonstrate that human RPA binds a UV damaged duplex DNA fragment preferentially. Complex formation between RPA and the UV-irradiated DNA is not affected by prior enzymatic photo-reactivation of the DNA, suggesting an affinity of RPA for the (6-4) photoproduct. We also show that Mg2+ in the millimolar range is required for preferential binding of RPA to damaged DNA. These findings identify a novel property of RPA and implicate RPA in damage recognition during the incision of UV-damaged DNA.

Original languageEnglish (US)
Pages (from-to)11607-11610
Number of pages4
JournalJournal of Biological Chemistry
Issue number20
StatePublished - Jan 1 1996


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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