Markel Martínez
Institut Pasteur, Paris
Bringing the right tool for the job: how RPA facilitates DNA replication and repair
DNA transcription, replication and repair require double-stranded DNA to be unwound. Replication Protein A (RPA) avidly coats exposed single-stranded DNA to protect it from nucleolytic degradation, and then needs to hand-off the ssDNA to the right protein partner for DNA replication or repair to take place. Our latest work unveiled multiple structures of archaeal RPA, explaining how RPA uses a conserved C-terminal winged-helix domain to regulate the activity of two key actors of the replisome: the DNA primase (PriSL) and the replicative DNA polymerase (PolD). Combining genetic and DNA polymerase assays with NMR, cryo-EM and crystallography approaches, our results explain a conserved mechanism for RPA-mediated interactions, which shares its ancestor with eukaryotic RPA and the CST telomere maintenance complex.
Multiple possible posttranslational modifications (PTMs) constitute an additional regulatory layer on eukaryotic RPA. The PTM status of RPA dictates which proteins will be recruited to ssDNA in a context-dependent manner, among more than 40 different interaction partners described so far. Our molecular understanding of this complex network of situational interactions remains limited, and my proposal aims to shed light on how RPA can shapeshift and recruit a vast number of DNA-processing partners with a multiscale integrative structural biology approach.
Selected references
- Martínez-Carranza M*, Vialle L,*, Madru C*, Cordier F*, Tekpinar AD, Haouz A, Legrand P, Le Meur RA, England P, Dulermo R, Guijarro IJ, Henneke G, Sauguet L. Communication between DNA polymerases and Replication Protein A within the archaeal replisome. Biorxiv (2024). DOI: 10.1101/2024.04.29.591592
- Madru C, Martínez-Carranza M, Laurent S, Alberti AC, Chevreuil M, Raynal B, Haouz A, Le Meur RA, Delarue M, Henneke G, Flament D, Krupovic M, Legrand P, Sauguet L. DNA-binding mechanism and evolution of replication protein A. Nature Communications 14, 2326 (2023). DOI: 10.1038/s41467-023-38048-w