Part of the ABC transporter DppABCDF involved in dipeptide transport (PubMed:11409543). Responsible for the translocation of the substrate across the membrane (Probable). The complex is composed of two ATP-binding proteins (DppD and DppF), two transmembrane proteins (DppB and DppC) and a solute-binding protein (DppA). Inactivation of the gene impairs growth on low concentrations of di-valine. Belongs to the binding-protein-dependent transport system permease family. OppBC subfamily. Truncated N-terminus.