Part of the ABC transporter complex FbpABC (TC 3.A.1.10.1) involved in Fe(3+) ions import. Probably responsible for the translocation of the substrate across the membrane (By similarity). The complex is composed of two ATP-binding proteins (FbpC), two transmembrane proteins (FbpB) and a solute-binding protein (FbpA). Belongs to the binding-protein-dependent transport system permease family. FbpB subfamily.