Biology subjects

Chevreuil, M.

Publications and source records attributed to Chevreuil, M..

2 recordsLinked to original sources

bioRxiv2023

Raynals, an online tool for the analysis of dynamic light scattering

Dynamic light scattering (DLS) is routinely employed to assess the homogeneity and size distribution profile of samples containing microscopic particles in suspension or solubilised polymers. In this work, we introduce Raynals, an user-friendly software for the analysis of single-angle DLS data that uses the Tikhonov-Phillips regularisation. Performance is evaluated on simulated and experimental data, generated by different DLS instruments, for several proteins and gold nanoparticles. DLS data can be easily misinterpreted and the simulation tools available in Raynals allow understanding of the limitations of the measurement and its resolution. It has been designed as a tool to address quality control of biological samples, during sample preparation and optimisation, and it helps in the detection of aggregates showing the influence of large particles. Last, Raynals provides flexibility in the way the data is presented, allows exporting publication-quality figures, it is free for academic use, and can be accessed online on the eSPC data analysis platform at spc.embl-hamburg.de.

biophysics↗

bioRxiv2022

DNA-binding mechanism and evolution of Replication Protein A

Replication Protein A (RPA) is a heterotrimeric single stranded DNA-binding protein with essential roles in DNA replication, recombination and repair, in both eukaryotic and archaeal cells. By using an integrative approach that combines three crystal structures, four cryo-EM structures in complex with single-stranded DNA (ssDNA) of different lengths, we extensively characterized RPA from Pyrococcus abyssi in different states. These structures show two essential features conserved in eukaryotes: a trimeric core and a module that promotes cooperative binding to ssDNA, as well as a newly identified archaeal-specific domain. These structures reveal for the first time how ssDNA is handed over from one RPA complex to the other, and uncover an unanticipated mechanism of self-association on ssDNA tracts. This work constitutes a significant step forward in the molecular understanding of the structure and DNA-binding mechanism of RPA, with far-reaching implications for the evolution of this primordial replication factor in Archaea and Eukarya.

biochemistry↗