Phase separation by ssDNA binding protein controlled via protein−protein and protein−DNA interactions
Gábor M. Harami, Zoltán Kovács, Rita Pancsa, János Pálinkás, Veronika Baráth, Krisztián Tárnok, András Málnási‐Csizmadia, Mihály Kovács
Abstract
SSB protein forms liquid-liquid phase-separated condensates in cellular-like conditions through multifaceted interactions involving all structural regions of the protein. SSB, ssDNA, and SSB-interacting molecules are highly concentrated within the condensates, whereas phase separation is overall regulated by the stoichiometry of SSB and ssDNA. Together with recent results on subcellular SSB localization patterns, our results point to a conserved mechanism by which bacterial cells store a pool of SSB and SSB-interacting proteins. Dynamic phase separation enables rapid mobilization of this protein pool to protect exposed ssDNA and repair genomic loci affected by DNA damage.