Part of the ABC transporter complex DasABC-MsiK involved in N,N'-diacetylchitobiose ((GlcNAc)2) uptake. Responsible for the translocation of the substrate across the membrane. The complex is composed of two ATP-binding proteins (MsiK), two transmembrane proteins (DasB and DasC) and a solute-binding protein (DasA). Induced by (GlcNAc)2 and (GlcNAc)3. Belongs to the binding-protein-dependent transport system permease family.