(A) Schematic representation of the cnfY promoter region (PcnfY) and the coding region which are part of the pJNS10 complementation vector [20]. Transcriptional start sites (TSS) identified in a previous study [18] and in this study (see Fig 2) are marked by arrows. (B) Y. pseudotuberculosis ΔcnfY (YP216) cells without vector or harboring vector pJNS10 (cnfY complementation vector; [20]), pJNS10 R1 (cnfY complementation harboring mutation R1; pBO6503), pJNS10 R1+2 (cnfY complementation vector harboring mutation R1+2; pBO6504), and pJNS11 (empty vector) were grown to exponential growth phase (OD600 = 0.5). Afterwards, samples were taken for SDS-PAGE as well as Western blot analysis with an antibody against CNFY. The experiment was performed at least in triplicate. (C) Survival and (D) body weight of BALB/c mice (n = 10/strain) was monitored for up to 14 days after oral infection via food pellets with 2x109 CFU of either Y. pseudotuberculosis YPIII harboring the empty vector pJNS11 (black line + black dots) or the cnfY mutant YP147 (cnfY::KanR) harboring the empty vector pJNS11 (grey line + grey squares) or the cnfY complementation vector pJNS10 (pPcnfY:cnfY+) including either the wild type (grey line + grey asterisk), the R1 (blue line + blue triangles), or the R1+2 (red line + red crosses) variant of the cnfY RNAT. Displayed data represent results from two individual experiments (biological replicates).