Mediates the ATP-dependent export of glutathione-conjugated substrates, such as heavy metal-glutathione conjugates. ATP hydrolysis is stimulated by glutathione binding. Protects cells against toxic heavy metal ions, such as silver and mercury ions. May also mediate the transport of glutathione-conjugated aromatic hydrocarbons, such as dinitrobenzene. Homodimer. Belongs to the ABC transporter superfamily. ABCB family. Heavy Metal importer (TC 3.A.1.210) subfamily.