No fluorescence was
observed when cells of E. coli WG709, expressing untagged, wild-type ProP, were examined in the same way. The same pattern of ProP localization was observed in cells without arabinose induction (Fig. 6, right) or after full arabinose induction (cultures supplemented with 13.3 mM arabinose). Interestingly, the polar/septal localization of ProP was strongest when the proportion of CL was high and CL was also concentrated at the poles and septa, as indicated by phospholipid headgroup analysis (Table 2) and CL visualization (Fig. 6, left) respectively. Thus, the localization of FlAsH-tagged ProP, and not its expression, was impaired in CL-deficient bacteria.