Table 2.
Steady-state response of SweetTrac1 mutants to three different sugars
| Constructs | D-Glucose (mM) | D-Mannose (mM) | D-Fructose (mM) |
|---|---|---|---|
| SweetTrac1 | 8 ± 1 | 107 ± 13 | 274 ± 42 |
| V69A | 14 ± 2 | 559 ± 95 | 411 ± 122 |
| V69I | 2 ± 0 | 23 ± 5 | 72 ± 11 |
| V69L | 11 ± 2 | 312 ± 57 | 97 ± 17 |
| I72V | 6 ± 1 | 219 ± 30 | 334 ± 44 |
| I72L | 17 ± 3 | 173 ± 45 | 197 ± 36 |
| V188A | 21 ± 3 | 1977 ± 467 | 851 ± 255 |
| V188I | 7 ± 1 | 69 ± 13 | 174 ± 24 |
| V188L | 5 ± 1 | 29 ± 6 | 29 ± 5 |
Mutagenesis analysis of SweetTrac1. Equilibrium exchange constant reported as estimate ± 95% confidence intervals (n = 4). Plotted curve fits are available in Figs. S3–S5. Mutant SweetTrac1I72A was nonfunctional despite proper plasma membrane localization (Fig. S2).