Evidence for direct contact between the RPA3 subunit of the human replication protein A and single-stranded DNA

Tonatiuh R Salas (1) , Irina Petruseva (2) , Olga Lavrik (2) , C. Saintome (1)

1 UPMC - Université Pierre et Marie Curie - Paris 6
2 ICBFM SB RAS - Institute of Chemical Biology and Fundamental Medicine [Novosibirsk, Russia]

Replication Protein A is a single-stranded (ss) DNAbinding 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.

Domaines: Sciences du Vivant [q-bio]; Chimie

Tonatiuh R Salas, Irina Petruseva, Olga Lavrik, C. Saintome. Evidence for direct contact between the RPA3 subunit of the human replication protein A and single-stranded DNA. Nucleic Acids Research, 2008, 37 (1), pp.38 - 46. ⟨10.1093/nar/gkn895⟩. ⟨hal-03344801⟩