Skip to main content
. 2018 Sep 19;4(9):eaas9365. doi: 10.1126/sciadv.aas9365

Fig. 5. N137A mutation impairs drug and ion transport by LmrA.

Fig. 5

(A) Ethidium efflux from preloaded cells containing LmrA-N137A was performed as described in Fig. 4F and was initiated by the addition of 25 mM glucose (+Glc) as a source of metabolic energy. Transport in the absence or presence of 50 mM Na2SO4 is compared with the Na+-stimulated activity for LmrA-WT. Line colors are the same as bar colors and refer to the same experimental conditions. (B) Ethidium transport in proteoliposomes was measured with artificial imposition of the same ion gradients as described in Fig. 4 (A and B). Where indicated, LmrA-WT activity was inhibited by inclusion of 1 mM Na-vanadate in the assay buffer. (C) H+ efflux was measured in cells loaded with pH probe 5(6)-carboxyfluorescein diacetate succinimidyl ester (CFDASE) to monitor the intracellular pH in the absence or presence of 125 mM Na2SO4 in the external buffer (based on up to nine independent measurements). Metabolic energy was generated in the cells by the addition of glucose at t = 0 min. (D) Erev was measured as described in Fig. 2G as a function of the log10 of the external Na+ concentration. The slope value was 58.8 ± 1.6 mV. Values in histograms show significance of fluorescence end levels and are expressed as means ± SEM (**P < 0.01, ****P < 0.0001, one-way ANOVA).

HHS Vulnerability Disclosure