Part of the ABC transporter FtsEX involved in cellular division. Important for assembly or stability of the septal ring. Homodimer (PubMed:10048040). Forms a membrane-associated complex with FtsX (PubMed:10048040). Interacts with FtsZ, independently of FtsX, FtsA or ZipA (PubMed:17307852). Associated with the membrane through an interaction with FtsX (PubMed:10048040). Localizes to the septal ring at the later stages of cell growth and remains there until division is complete (PubMed:14729705). This localization is dependent on localization of FtsZ, FtsA and ZipA, but not on the downstream division proteins FtsK, FtsQ or FtsI (PubMed:14729705). Inactivation results in a filamented cellular morphology, but not in a temperature-sensitive phenotype. Belongs to the ABC transporter superfamily.