Essential cell division protein that forms a contractile ring structure (Z ring) at the future cell division site. The regulation of the ring assembly controls the timing and the location of cell division. One of the functions of the FtsZ ring is to recruit other cell division proteins to the septum to produce a new cell wall between the dividing cells. Binds GTP and shows GTPase activity (By similarity). Required for division ring constriction (PubMed:33903747). Homodimer. Polymerizes to form a dynamic ring structure in a strictly GTP-dependent manner. Interacts directly with several other division proteins (By similarity). Interacts with SepF (PubMed:34103513). Assembles at midcell at the inner surface of the cytoplasmic membrane. Viable, but have fewer colony-forming units compared to wild-type. Cells are very heterogeneously sized and misshapen, and have a notable amount of cellular debris. Loss of cell division. No effect on Z1 ring formation. FtsZ1/FtsZ2 double deletion mutant cells show various division defects, including fragmentation, budding, polar tubulation and fission resulting in DNA-containing particles, which are able to remain viable and propagate without regular cell division. Belongs to the FtsZ family.