Involved in the uptake of iron. Probably responsible for the translocation of the substrate across the membrane. Part of the ABC transporter complex FeuABC/YusV involved in import of the catecholate siderophores bacillibactin and enterobactin. The complex is composed of one ATP-binding protein (YusV), two transmembrane proteins (FeuB and FeuC) and a solute-binding protein (FeuA). Induced by Btr in iron-limited conditions. Belongs to the binding-protein-dependent transport system permease family. FecCD subfamily.