Essential cell division protein that must bind to FtsZ for division to occur (PubMed:20864042, PubMed:29119622). Critical coordinator of envelope constriction through its interaction with FtsZ (PubMed:29119622). Promotes the formation of highly curved FtsZ filaments, reduces the GTPase activity of FtsZ and stabilizes FtsZ polymers (PubMed:20864042). May regulate FtsZ function by modulating its superstructure (PubMed:20864042). Does not bind to glutathione (PubMed:20864042). Homodimer (PubMed:29119622). Interacts with FtsZ filaments (PubMed:20864042, PubMed:29119622). Probably interacts with the GTPase domain of FtsZ (PubMed:29119622). Colocalizes with FtsZ at the division site. Cell cycle regulated at the transcript and protein levels. mRNA levels peak in predivisional cells. Deletion is lethal. Depletion results in cells that are elongated and grow into smooth filaments. Belongs to the GST superfamily.