FIG. 2.

Physical organization of R. etli rseF-rpoE4 and tcrX genes and expression under different stress conditions. (A) Genomic organization of the rseF-rpoE4 and tcrX region. The fragment cloned upstream of uidA into pBBMCS53 is indicated by the lower diagram. (B and C) Levels of expression of the rpoE4-uidA (B) and trcX-uidA (C) transcriptional fusions under oxidative, saline, or osmotic stress. Exponential-phase cultures (OD₆₀₀, ∼0.3) were grown on MM, and CE3/pJMS24 and CE3/pJMS25 strains were incubated with 1 mM H₂O₂, 100 mM NaCl, 10% (wt/vol) sucrose (Suc), or 40 μM methyl viologen (PQ) for 45 min. Specific activity (Sp Act) was determined by using β-glucuronidase activity. The data shown are the averages of results from at least three independent experiments, and the vertical bars represent the standard deviations. −, no stress treatment.