Figure 3.

Drug-free EmrE is sensitive to pH. Full ¹H-¹⁵N TROSY-HSQC spectra of drug-free WT EmrE in DLPC/DHPC isotropic bicelles at three pH values collected at 45°C (A) and 25°C (B). The pH of each spectrum is indicated by its color as designated in the figure. All spectra in the full pH titration datasets are shown in Figs. S1 (45°C) and S3 (25°C). Circles highlight several residues that remain in the slow exchange regime at 25°C at low pH.