Probing a positioning system for high-copy cargoes at the single-molecule level

Unlike eukaryotes, which utilize linear motor proteins to facilitate intracellular transport and organization, bacteria use the ParAB family of proteins to spatially organize protein cargoes involved in diverse aspects of bacterial physiology. For example, carboxysomes are Bacterial Microcompartments (BMCs) crucial for carbon fixation in cyanobacteria and proteobacteria. Recently, a ParA-like ATPase, termed Maintenance of carboxysome distribution A (McdA) and its partner protein, McdB, were revealed to position carboxysomes.