FIG 3.
NPN efflux assays. Efflux of NPN from cells preloaded with this dye was initiated by adding 50 mM glucose. A rapid loss of fluorescence intensity indicates AcrAB-mediated efflux of NPN. The excitation and emission wavelengths were set at 340 nm and 410 nm, respectively. For clarity, data for AcrB suppressors mapping to the porter domain are shown in panel A, whereas those for suppressors mapping to the TM domain are shown in panel B. Slopes (m) and tefflux50% values are shown in Table 5. a.u., arbitrary units.