Dynamic Structural Organization of Biomolecular Condensates in <i>Escherichia coli</i> Cells

Hierarchical structures of biomolecular condensates in living cells are essential for cellular functions, particularly in orchestrating complex reactions through synergistic cooperation. However, our understanding of these structures remains limited, because controlling the hierarchical structures of condensates in living cells can be difficult. Here we create an artificial condensate system in model prokaryotic <i>Escherichia coli</i> cells via coexpressing two distinct intrinsically disordered proteins. By modulating the homotypic and heterotypic interactions between the two proteins, condensates with differential structural organization (cophase and multiphase separation) were successfully constructed and dynamically controlled via physical or chemical cues from the environments. <i>In vitro</i> reconstitutions further supported the underlying physicochemical principles of dynamic condensate organization. This study not only deepens our understanding of the structural organization of biomolecular condensates but also provides a useful strategy for dynamic regulation of synthetic condensates in living cells.