Figure 3.

Analysis of barA and uvrY transcription in the presence and absence of Crp in Y. pseudotuberculosis. The empty vector pAKH85 (V) or its crp⁺ derivative pAKJH37 (pcrp⁺) were transformed into Y. pseudotuberculosis YPIII and YP89 (Δcrp) harboring a barA-lacZ fusion (pKB6) (A) or an uvrY-lacZ fusion (pKB7) (B). The bacteria were grown overnight in LB medium at 25°C. β-Galactosidase activity from overnight cultures was determined and is given in μmol min⁻¹ mg⁻¹ for comparison. The data represent the average ±SD from at least three different experiments each done in duplicate. (C) Expression of CsrB in the presence and absence of UvrY and/or Crp. Total RNA of Y. pseudotuberculosis wildtype strain YPIII and the mutant strains YP89 (Δcrp), YP120 (ΔuvrY), and YP128 (ΔcrpΔuvrY) harboring the empty vector pAKH85 or the uvrY-encoding plasmid pAKH75 or crp-encoding plasmid pAKH37 grown at 25°C was prepared, and analyzed by northern blotting with a CsrB-specific probe. YP69 (ΔcsrB) was used as negative control.