Fig. 3.

The Y. pestis yfeAB mntH double mutant does not actively transport ⁵⁴Mn into the cell. Strains were grown at 37 °C in Chelex-100-treated PMH2, and ⁵⁴MnCl₂ was added during early exponential phase to start the Mn uptake assay. For energy-independent binding of ⁵⁴Mn (closed symbols), CCCP was added 10 min prior to radioisotope addition. Strains used were Pgm⁺: KIM6+ (Yfe⁺ MntH⁺) and KIM6-2122.1+ [Yfe⁻ (ΔyfeAB2031.1) MntH⁻ (ΔmntH2122)]. Results are reported as percentage uptake of ⁵⁴Mn per 0.4 OD₆₂₀ unit (cell density). One of two independent experiments with similar results is shown.