title: Evidence for direct contact between the RPA3 subunit of the human replication protein A and single-stranded DNA.
abstract: Replication Protein A is a single-stranded (ss) DNA-binding protein that is highly conserved in eukaryotes and plays essential roles in many aspects of nucleic acid metabolism, including replication, recombination, DNA repair and telomere maintenance. It is a heterotrimeric complex consisting of three subunits: RPA1, RPA2 and RPA3. It possesses four DNA-binding domains (DBD), DBD-A, DBD-B and DBD-C in RPA1 and DBD-D in RPA2, and it binds ssDNA via a multistep pathway. Unlike the RPA1 and RPA2 subunits, no ssDNA-RPA3 interaction has as yet been observed although RPA3 contains a structural motif found in the other DBDs. We show here using 4-thiothymine residues as photoaffinity probe that RPA3 interacts directly with ssDNA on the 3'-side on a 31 nt ssDNA.
authors.affiliation: Laboratoire de Biophysique Moléculaire, Cellulaire et Tissulaire, CNRS-ParisVI-Paris XIII-UMR 7033, Paris, France.
authors.forename: Tonatiuh Romero
authors.initials: TR
authors.lastname: Salas
authors.forename: Irina
authors.initials: I
authors.lastname: Petruseva
authors.forename: Olga
authors.initials: O
authors.lastname: Lavrik
authors.forename: Carole
authors.initials: C
authors.lastname: Saintomé
mesh_terms: D001665:Binding Sites; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D011485:Protein Binding; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D051716:Replication Protein A / Q000378:metabolism*; D013936:Thymidine / Q000031:analogs & derivatives / Q000737:chemistry / Q000528:radiation effects
chemical_list: C414668:4-thiothymidine; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D021122:Protein Subunits; C534779:RPA3 protein, human; D051716:Replication Protein A; D013936:Thymidine