Part of an ABC transporter complex involved in the uptake of all common nucleosides. The complex is composed of two ATP-binding proteins (NupA), two transmembrane proteins (NupB and NupC) and a solute-binding protein (BmpA). Expression is induced in the presence of purine via PurR. Mutant is unable to grow on inosine as a sole purine source. Belongs to the BMP lipoprotein family.