Contributes to the efficiency of the cell division process by stabilizing the polymeric form of the cell division protein FtsZ. Acts by promoting interactions between FtsZ protofilaments and suppressing the GTPase activity of FtsZ. Interacts directly with FtsZ. Monomer in solution. Colocalizes with FtsZ at division sites. Localization to the Z ring is dependent on FtsZ and independent of FtsA, ZipA, ZapA or ZapB. Mutants divide almost normally under standard growth conditions. Belongs to the ZapC family.