title: RPA involvement in the damage-recognition and incision steps of nucleotide excision repair.
abstract: Human replication protein (RPA) functions in DNA replication, homologous recombination and nucleotide excision repair. This multisubunit single-stranded DNA-binding protein may be required to make unique protein-protein contacts because heterologous single-stranded binding proteins cannot substitute for RPA in these diverse DNA transactions. We report here that, by using affinity chromatography and immunoprecipitation, we found that human RPA bound specifically and directly to two excision repair proteins, the xeroderma pigmentosum damage-recognition protein XPA (refs 8, 9) and the endonuclease XPG (refs 10-13). Although it had been suggested that RPA might function before the DNA synthesis repair stage, our finding that a complex of RPA and XPA showed a striking cooperativity in binding to DNA lesions indicates that RPA may function at the very earliest stage of excision repair. In addition, by binding XPG, RPA may target this endonuclease to damaged DNA.
authors.affiliation: Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.forename: L A
authors.initials: LA
authors.lastname: Henricksen
authors.forename: M S
authors.initials: MS
authors.lastname: Wold
authors.forename: C J
authors.initials: CJ
authors.lastname: Ingles
mesh_terms: D002846:Chromatography, Affinity; D004247:DNA / Q000378:metabolism; D004260:DNA Repair / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004720:Endonucleases; D005092:Exonucleases / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins; D011233:Precipitin Tests; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D051716:Replication Protein A; D014157:Transcription Factors; D051760:Xeroderma Pigmentosum Group A Protein; D000099250:DNA Excision Repair Protein ERCC-5
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D004720:Endonucleases; D005092:Exonucleases; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D051716:Replication Protein A; D014157:Transcription Factors; D051760:Xeroderma Pigmentosum Group A Protein; D000099250:DNA Excision Repair Protein ERCC-5; C497167:RPA1 protein, human; C497314:XPA protein, human