The ATP-binding cassette (ABC) transporter of mitochondria (Atm1) mediates iron homeostasis in eukaryotes, while the prokaryotic homolog from Novosphingobium aromaticivorans (NaAtm1) can export glutathione derivatives and confer protection against heavy metal toxicity. To establish the structural framework underlying the NaAtm1 transport mechanism, we determined eight structures by X-ray crystallography and single particle cryo-EM in distinct conformational states, stabilized by individual disulfide crosslinks and nucleotides. As NaAtm1 progresses through the transport cycle, conformational changes in transmembrane...