Part of the ABC transporter complex LpqY-SugA-SugB-SugC, which is highly specific for uptake of trehalose. Involved in the recycling of extracellular trehalose released from trehalose-containing molecules synthesized by M.tuberculosis. Trehalose uptake is essential for virulence. Probably responsible for energy coupling to the transport system. The complex is composed of two ATP-binding proteins (SugC), two transmembrane proteins (Suga and SugB) and a solute-binding protein (LpqY). Mutants show no growth on trehalose as the sole carbon and energy source, but grow normally on glucose. They secrete substantial amounts of trehalose during growth on glycerol. Belongs to the ABC transporter superfamily.