Clusters of bacterial RNA polymerase are biomolecular condensates that assemble through liquid–liquid phase separation

TLDR

Bacterial cells, once thought to lack internal structure, actually contain subcellular compartments whose formation was unclear until recent microscopy revealed liquid–liquid phase separation as a mechanism for organizing intracellular space. We show that liquid–liquid phase separation also occurs in bacteria, indicating it is a common mechanism for intracellular organization across prokaryotes and eukaryotes.

Abstract

Significance Bacterial cells are small and were long thought to have little to no internal structure. However, advances in microscopy have revealed that bacteria do indeed contain subcellular compartments. But how these compartments form has remained a mystery. Recent progress in larger, more complex eukaryotic cells has identified a novel mechanism for intracellular organization known as liquid–liquid phase separation. This process causes certain types of molecules to concentrate within distinct compartments inside the cell. Here, we demonstrate that the same process also occurs in bacteria. This work, together with a growing body of literature, suggests that liquid–liquid phase separation is a common mechanism for intracellular organization in both eukaryotic and prokaryotic cells.