Part of the ABC transporter complex GsiABCD involved in glutathione import. Responsible for energy coupling to the transport system. ATP + glutathione(out) + H2O = ADP + glutathione(in) + H(+) + phosphate The complex is composed of two ATP-binding proteins (GsiA), two transmembrane proteins (GsiC and GsiD) and a solute-binding protein (GsiB). Belongs to the ABC transporter superfamily. Glutathione importer (TC 3.A.1.5.11) family.