Figure 1.

A type 2 secretion system is present and functional in C. rodentium. (a) A complete T2SS operon is present in the C. rodentium genome and 4 predicted effector proteins are located in close proximity to the operon (colored red and grey respectively). (b) Selected T2SS gene expression changes calculated in C. rodentium cultured in DMEM for 3 hours using a ΔΔCt method with dnaQ and C. rodentium grown in LB media used as reference. n = 4, Wilcoxon signed-rank test, error bars are standard error of the mean. (c) Growth dynamics of wild-type (WT) or T2SS knock-out (ΔgspK) strain in LB measured by optical density of the culture. n = 3, error bars are standard deviation. (d) Protein secretion assay showing secretion of putative effector proteins in the WT and ∆gspK strains. Western blot detection of C-terminally V5-tagged ROD_44811 and ROD_44831 proteins expressed ectopically in WT and ∆gspK strains. Ponceau staining for BSA shown to demonstrate equal loading. n = 3 independent experiments, representative blots shown.