Figure 1.

Accumulation of [³H]l-alanine in intact cells. Cells were grown in minimal medium and suspended in the same medium. The transport assay was initiated by adding [³H]l-alanine (60 Ci mmol⁻¹) to a final concentration of 10 μmol/L and then incubated at 37°C. An aliquot (100 μL) of the cell suspension was filtered through a membrane filter with a 0.22 μm-pore size, and then washed twice with 3 mL each of pre-warmed minimal medium. Values presented are the means of three independent experiments with standard deviations. Symbols: ▵, MLA301; ○, MLA301ΔalaE; □, MLA301ΔalaE/pAlaE.