Table S1.

Correlation between ligand binding, serotonin transport activity, and accessibility to MTSEA

Strain	Binding ratio, reserpine/TBZ	Serotonin uptake, pmol per 20 min	IC50 for MTSEA, μM
wild-type	0.57 ± 0.02	1.47 ± 0.27	205 ± 78
Y419F	0.64 ± 0.37	1.57 ± 0.31	80 ± 8
R218A	1.26 ± 0.01	0.09 ± 0.04	57 ± 7
Y419A	3.50 ± 0.67	0.02 ± 0.02	9 ± 0.3
R218H	5.57 ± 0.88	0.02 ± 0.01	24 ± 0.3
Y419S	5.88 ± 1.36	0.02 ± 0.01	1.9 × 10−4 ± 0.05

Reserpine and TBZ binding and serotonin uptake values were taken from Fig. 2. IC₅₀ values for inhibition by MTSEA were calculated from Fig. S4 using Origin 9.2 software (OriginLab).