Amino acid transporter with broad substrate specificity (By similarity). Required for resistance to methyl viologen (PubMed:12410826). May function with OmpD porin (PubMed:12410826). Mutants show increased sensitivity to methyl viologen. Belongs to the drug/metabolite transporter (DMT) superfamily. Aromatic amino acid/paraquat exporter (ArAA/P-E) (TC 2.A.7.17) family.