Fig. 4: A mesoscopic, molecularly-informed phase field model was developed to reproduce the hollow co-condensate formation.

a Simulations for FUS-ERG-DNA hollow co-condensate formation. (i) FUS-ERG molecules form biomolecular condensates with dsDNA containing GGAA microsatellites on their surface. dsDNA (\({\zeta }_{{DNA}}\)) and protein (\({\zeta }_{{protein}}\)) concentrations are represented. (ii) dsDNA molecules are transited into protein droplets, triggering the formation of hollow co-condensates. Order parameters denoting protein-DNA complex concentration (\(\eta\)), dsDNA concentration (\(\chi\)) and hydrophobic and hydrophilic distributions within condensates (\({{{\rm{\phi }}}}\)) are represented. (iii) Hollow architecture is observed in steady states of the model proposed. DNA is coupled with hydrophobic region of the protein-DNA complex. b Distributions of simulated dsDNA concentration (\(\chi\)) within hollow architectures. c States diagram of simulated structures by varying initial states in a(i). Blue cross: One-phase, which is a homogeneous state; Orange dot: homogeneous condensates; Green circle: hollow co-condensates. d Simulations for PRM-RNA hollow co-condensate formation. (i) RNA first forms tadpole-like diblock copolymer with PRM protein. Order parameter denoting protein-RNA complex concentration (\(\eta\)), RNA concentration (\(\chi\)) and hydrophobic and hydrophilic distributions within copolymer (\(\phi\)) are represented. (ii) Hollow structure is observed in simulation results. RNA is coupled with both hydrophobic and hydrophilic region of protein-RNA complex. e Distributions of simulated RNA concentration (\(\chi\)) within hollow structures. Source data are provided as a Source Data file.