Role of a conserved glycine triplet in the NSS amino acid transporter KAAT1

► KAAT1 Gly 85-87 mutants are expressed on the membrane surface although at different level. ► Mutants showed altered interaction with cations. ► Cross-linking of cysteine mutants by oxidative treatment inhibited transport activity. ► Na+ protected position 87 from oxidation both directly and indirectly. ► Glycine flexibility is involved in KAAT1 function and its interaction with cations.