FIG. 2.
In vitro expression kinetics of reporter fusions for genes encoding SPI2 effectors or components of the SPI2-T3SS. Reporter strains representing different functional groups in the SsrAB virulon were grown in vitro under SPI2-inducing conditions (PCN medium-0.4 mM Pi, pH 5.8). Cells were harvested at various time points, and equal amounts of cells adjusted by OD600 were lysed for the quantification of Luc activities. Expression levels of reporter fusions to SPI2 genes encoding structural components of the T3SS or effector proteins are indicated in black or white histograms, respectively. Expression levels of reporter fusions to genes for effector proteins that are located outside of SPI2 are indicated by gray histograms. Luc activities are expressed with linear or logarithmic scaling in the large histograms and insets, respectively. A representative growth curve of S. enterica serovar Typhimurium in PCN-0.4 mM Pi, pH 5.8, minimal medium is shown on the upper right, and all reporter strains showed similar growth characteristics. The error bars indicate standard deviations.