Mutations to amino acid side chains predicted to coordinate K⁺ disrupt K⁺-induced reverse transport. Whole-cell current recording experiments were performed under reverse transport conditions (130 mM NaMes and 5 mM Glu⁻ in the pipette solution; extracellular solution was switched from NMGMes to KMes [both 140 mM, indicated by gray bar]) to induced reverse transport at V = 0 mV. (A) Reverse transport current in EAAC1_WT. (B) Typical reverse transport current for EAAC1_Y98F (red) and EAAC1_D454N (black). Maximum of reversed transport current of all mutants shown in C. Error bars represent SD. The locations of the mutated amino acids are illustrated in D.