Figure 5. The GAF domain of PtsP is dispensable for its role in biofilm formation.

A. Schematic of the PTS^Ntr phosphorylation cascade. Phosphate is transferred by EI^Ntr (encoded by ptsP) from phosphoenolpyruvate (PEP) to Npr (encoded by ptsO). Npr in turn transfers the phosphate to EII^Ntr (encoded by ptsN), which is thought to directly exert regulatory activity. B. Colony morphologies (6 d) of the indicated strains, including a strain in which the native copy of ptsP has been markerlessly replaced with a copy deleted for nucleotides 49–492, which encode the 148-residue GAF domain of EI^Ntr. C. Congo red binding by the indicated colonies. Mean values of at least 3 replicates are shown; error bars indicate ± 1 standard deviation. **, p < 0.01 relative to amrZ. D. c-di-GMP levels in the indicated colonies. Mean values of at least 3 replicates are shown; error bars indicate ± 1 standard deviation. *, p < 0.05 relative to amrZ.