Discovery and characterization of a novel family of prokaryotic nanocompartments involved in sulfur metabolism

Prokaryotic nanocompartments, also known as encapsulins, are a recently discovered proteinaceous organelle-like compartment in prokaryotes that compartmentalize cargo enzymes. While initial studies have begun to elucidate the structure and physiological roles of bioinformatic evidence suggests great diversity encapsulin nanocompartments remains unexplored. Here, we describe novel freshwater cyanobacterium Synechococcus elongatus PCC 7942. This nanocompartment is upregulated upon sulfate starvation encapsulates cysteine desulfurase enzyme via an N-terminal targeting sequence. Using cryo-electron microscopy, determined complex 2.2 Å resolution. Lastly, biochemical characterization demonstrated activity enhanced encapsulation. Taken together, our discovery, structural analysis, enzymatic this prokaryotic provide foundation for future seeking understand role various bacteria.