Part of the ABC transporter FtsEX involved in asymmetric cellular division facilitating the initiation of sporulation. May act as an importer, possibly at the top of a hierarchical cascade leading to the correct temporal initiation of sporulation. Acts upstream of the histidine kinases KinA, KinB and KinC, the RapA phosphatase and the Spo0A sporulation protein. Interacts with FtsE (Probable). Interacts with FloT (PubMed:23651456). Unlike the E.coli ortholog, localization is not restricted to division septa, nor is it dependent on FtsZ. Present in detergent-resistant membrane (DRM) fractions that may be equivalent to eukaryotic membrane rafts; these rafts include proteins involved in signaling, molecule trafficking and protein secretion (PubMed:23651456). Cells lacking this gene and ftsE, the previous gene in the operon, delay sporulation onset, as a result of which they form a medial rather than polar septum at the onset of sporulation. This is presumably due to slower phosphorylation and activation of the spo0A transcriptional regulator. However, at later time points these cells undergo polar division and eventually form smaller than wild-type mature spores. Belongs to the ABC-4 integral membrane protein family. FtsX subfamily.