Figure 3. FimL, CyaB, and Vfr are required for exoT transcription and TM.

All strains harbor the PexoT-lacZ transcriptional reporter fusion integrated at the CTX site as a readout for transcription of the T3SS. β-galactosidase activity was measured in the presence or absence of calcium. Gene names denote in-frame deletions in PAO1 (A and C) or PA103 (B and D). (A and B) Shown are mean of 12 data points from triplicate samples from 2 or 3 experiments. (C and D). Shown is the mean diameter from a minimum of 5 colonies from 2 or 3 experiments. Error bars denote SD. (***) indicates P<0.001 compared to the wild type strain grown in the absence of Ca²⁺.