title: Sequential binding of DNA repair proteins RPA and ERCC1 to XPA in vitro.
abstract: Recent studies have shown that many proteins are involved in the early steps of nucleotide excision repair and that there are some interactions between nucleotide excision repair proteins, suggesting that these interactions are important in the reaction mechanism. The xeroderma pigmentosum group A protein (XPA) was shown to bind to the replication protein A (RPA) or the excision repair cross complementing rodent repair deficiency group 1 protein (ERCC1), and these interactions might be involved in the damage-recognition and/or incision steps, of nucleotide excision repair. Here we show that the XPA regions required for the binding to the 70 and 34 kDa subunits of RPA are located in the middle and on N-terminal regions of XPA, respectively. These regions do not overlap with the ERCC1-binding region of XPA, and a ternary protein complex of RPA, XPA and ERCC1 was detected in vitro. In addition, using the surface plasmon resonance biosensor, the binding of RPA and ERCC1 to XPA was investigated. The dissociation constants (KD) of RPA and ERCC1 with XPA were 1.9 x 10(-8 )and 2.5 x 10(-7) M, respectively. Moreover, our results suggest the sequential binding of RPA and ERCC1 to XPA.
authors.affiliation: Division of Cellular Genetics, Institute for Molecular and Cellular Biology, Osaka University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Saijo
authors.forename: I
authors.initials: I
authors.lastname: Kuraoka
authors.forename: C
authors.initials: C
authors.lastname: Masutani
authors.forename: F
authors.initials: F
authors.lastname: Hanaoka
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D001665:Binding Sites; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004720:Endonucleases; D004926:Escherichia coli / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D051716:Replication Protein A; D051760:Xeroderma Pigmentosum Group A Protein
chemical_list: D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D011506:Proteins; C497167:RPA1 protein, human; D011993:Recombinant Fusion Proteins; D051716:Replication Protein A; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein; D005982:Glutathione Transferase; C071447:ERCC1 protein, human; D004720:Endonucleases