divisome

The divisome is a dynamic multi-protein complex that governs bacterial cell division. It localizes to the future division site and coordinates the assembly of the septal cell wall and the physical constriction of the cell envelope, producing two daughter cells. The complex integrates cytoskeletal, membrane-associated, and enzymatic components to accomplish cytokinesis.

In many bacteria, assembly begins with the polymerization of FtsZ into a Z-ring at midcell, tethered to the inner membrane by FtsA and ZipA. Early divisome proteins recruit additional membrane-spanning components, including FtsK, FtsQ, FtsL and FtsB, while later arriving proteins FtsW and FtsI drive septal peptidoglycan synthesis. FtsN is among the last to arrive and helps activate constriction.

The divisome is regulated by spatial cues such as the MinCDE system, which prevents division at cell poles, and nucleoid occlusion, which blocks division over unsegregated chromosomes. The complex coordinates synthesis and remodeling of peptidoglycan with constriction, coupling energy from GTP hydrolysis by FtsZ to the activities of PBPs and transglycosylases.

Although the exact composition varies among species, the divisome represents the core machinery for bacterial cytokinesis in most Gram-negative and many Gram-positive bacteria. It is a target of interest for antibiotics that disrupt cell division.