FIG. 5.

β-Galactosidase assay to determine activity levels of promoter regions across the cj0173c-tonB1 region of the C. jejuni NCTC 11168 genome. Reporter gene assay of pMW10 with no promoter region (negative control) and the promoter regions upstream of housekeeping gene metK (positive control) (59), chuA (iron-responsive control) (47), and cj0176c, cj0177, cj0178, and exbB1. Promoter activity levels were determined from β-galactosidase activity of iron-limited (20 μM Desferal) or iron-replete (40 μM FeSO₄) C. jejuni 480 cultures containing reporter constructs (Table 1) and grown in MHB for 5 h at 37°C. All conditions were tested in triplicate in two independent assays. Each data point is the mean of six replicates, with the standard error of the mean shown.