Bacteria have distinct challenges to organize their cellular pathways as they generally lack membrane-bound organelles. In eukaryotes, membraneless organelles called biomolecular condensates provide distinct liquid-liquid phase separated structures that organize cellular components. We discovered the first biomolecular condensate type of organelle in bacteria that we termed Bacterial Ribonucleoprotein bodies (BR-bodies) composed of the RNA degradosome multi-protein complex and cellular mRNAs. Here we will describe how the bacterium Caulobacter crescentus organizes ribonucleases, RNA helicases, and mRNA substrates into BR-bodies which stimulate mRNA decay. We find that the intrinsically disordered region of RNase E controls the subcellular localization pattern of BR-bodies, and its ability to form BR-bodies is conserved across α-proteobacteria. We propose that the formation of similar biomolecular condensate organelles may provide a particularly effective strategy for spatially organizing biochemical pathways in bacteria.
