Salas Tonatiuh Romero, Petruseva Irina, Lavrik Olga, Saintomé Carole
Laboratoire de Biophysique Moléculaire, Cellulaire et Tissulaire, CNRS-ParisVI-Paris XIII-UMR 7033, Paris, France.
Nucleic Acids Res. 2009 Jan;37(1):38-46. doi: 10.1093/nar/gkn895. Epub 2008 Nov 14.
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.
复制蛋白A是一种单链（ss）DNA结合蛋白，在真核生物中高度保守，在核酸代谢的许多方面发挥着重要作用，包括复制、重组、DNA修复和端粒维持。它是一种异源三聚体复合物，由三个亚基组成：RPA1、RPA2和RPA3。它具有四个DNA结合结构域（DBD），RPA1中的DBD-A、DBD-B和DBD-C以及RPA2中的DBD-D，并且它通过多步途径结合ssDNA。与RPA1和RPA2亚基不同，尽管RPA3包含在其他DBD中发现的结构基序，但尚未观察到ssDNA-RPA3相互作用。我们在此使用4-硫胸腺嘧啶残基作为光亲和探针表明，RPA3在31 nt ssDNA的3'侧直接与ssDNA相互作用。
