FIG. 3.

Elimination of the site of phosphorylation on CpxR eliminates the dependence of porin expression on CpxA. The strains used were MDG147 (wild type), EPB54-012 (cpxA::kan), EPB128 (cpxRD51A), and EPB218 (cpxRD51A cpxA::cat). Porin expression was measured as CFP fluorescence (corresponding to ompC) (open bars) and YFP fluorescence (corresponding to ompF) (gray bars) in arbitrary units (AU), normalized by OD₆₀₀, for strains grown in glucose minimal medium to the mid-log phase (see Materials and Methods). The bars indicate the means of at least three independent experiments, and the error bars indicate the standard deviations.