Résumé
The ParABS system is composed of three components: a centromeric sequence, parS, and two proteins, the ParA (ATPase) and the ParB DNA binding proteins. Hundreds of ParB proteins assemble dynamically to form nucleoprotein parS-anchored complexes (ParBS) that serve as substrates for ParA molecules to catalyze positioning and segregation events. We address the theoretical modeling of ParBS with a Lattice Gas models and compare it to experiments [1]. We give evidences that (i) ParBS is formed via a Liquid-Liquid Phase Separation in the metastable region of the phase diagram and (ii) this nucleation is catalyzed with the parS sequence [1].[1] Guilhas, Walter,... & Nollmann (2020). ATP-driven separation of liquid phase condensates in bacteria. Mol. Cell, 79, 293-303.