FtsZ is a self-assembling protein that forms the contractile ring guiding the cell division machinery in most bacteria. FtsZ is structurally homologous to tubulin, the subunit of eukaryotic microtubules. FtsZ monomers associate head-to-tail forming single-stranded filaments that hydrolyze GTP, in a partially understood process. However, how FtsZ filaments organize in the dynamic division ring is still a challenging problem. Rather than forming a well-defined structure, such as band or tubule, FtsZ filaments laterally associate among them in a relatively disordered fashion. FtsZ filaments bind partner and regulatory proteins, including those tethering them to the inner face of the plasma membrane.