Table S1.
GltPh kinetic parameters determined by HS-AFM
| Condition | τ(up), s | k(out-in), s−1 | p(up) | τ(down), s | k(in-out), s−1 | p(down) | ΔG(translation), kBT | Q, % | ΔG(activation), kBT |
| Apo (no substrates) | 6.6 | 0.15 | 0.79 | 1.8 | 0.56 | 0.21 | 1.3 | 27 | 1.0 |
| Na+ (10 × Kd of Na+) | 33.0 | 0.03 | 0.94 | 2.1 | 0.47 | 0.06 | 5 | ||
| Transport (Na+ + Asp) | 11.1 | 0.08 | 0.84 | 2.1 | 0.48 | 0.16 | 1.7 | 39 | 0.5 |
| TBOA (blocker) | 100.0 | 0.01 | 0.98 | 2.3 | 0.42 | 0.02 | 1 |
τ(up) (column 1), τ(down) (column 4), and Q (column 8) were determined directly in HS-AFM experiments. The rate constants k(out-in) (column 2), and k(in-out) (column 5) are calculated as 1/τ(up) and 1/τ(down), respectively. The state probabilities p(up) (column 3) and p(down) (column 6) are calculated according to Eqs. S4 and S5, respectively. The free-energy differences between states (column 7) were calculated from τ(up) and τ(down) according to Eq. S2. The free energy of protomer activation was calculated from Q according to Eq. S1.