Table 2.
Expression analysis of the GFP reporter fusions
| Fusion | Strain | 10 mM MgCl2 | 10 μM MgCl2 | 100 μM FeCl3 | 10 mM MgCl2 100 μM FeCl3 | 10 μM MgCl2 100 μM FeCl3 |
| pmrC::GFP | WT | 6.06 (0.18) | 16.8 (1.42) | 70.53 (3.84) | 27.39 (4.41) | 83.2 (3.21) |
| pmrA - | 1.00 (0.01) | 1.02 (0.02) | 1.08 (0.03) | 1.03 (0.03) | 1.16 (0.12) | |
| mig-13::GFP | WT | 6.17 (1.55) | 13.50 (2.02) | 35.81 (4.67) | 17.86 (5.04) | 49.23 (5.43) |
| pmrA - | 2.69 (0.11) | 4.32 (0.48) | 5.2 (0.09) | 2.67 (0.16) | 9.64 (1.19) | |
| aroQ::GFP | WT | 2.32 (0.22) | 20.39 (1.54) | 19.39 (0.53) | 4.38 (0.19) | 19.48 (2.07) |
| pmrA - | 1.06 (0.02) | 1.09 (0.02) | 1.71 (0.09) | 1.02 (0.01) | 1.09 (0.03) | |
| yibD::GFP | WT | 1.25 (0.02) | 1.67 (0.26) | 33.35 (7.01) | 27.52 (5.64) | 52.46 (8.98) |
| pmrA - | 1.26 (0.02) | 1.21 (0.06) | 1.30 (0.02) | 1.14 (0.02) | 1.81 (0.44) | |
| sseJ::GFP | WT | 7.68 (1.55) | 11.25(1.46) | 22.58 (1.01) | 3.80 (1.13) | 8.03 (1.27) |
| pmrA - | 5.64 (0.72) | 8.72 (1.05) | 7.35 (1.55) | 2.99 (0.43) | 6.47 (1.36) |
All experiments were performed twice. Values indicate the average mean peak fluorescence measurements of at least three samples for the populations grown under the conditions indicated for one representative experiment. Values in parentheses represent standard deviations. All values are expressed in arbitrary units. Strains used: WT = ATCC14028s and pmrA- = pmrA::Tn10d. For pmrC, aroQ, mig-13 and yibD, values represented in the table correspond to experiments performed at pH 7.7. Similar results were obtained at pH 5.8 (data not shown). For sseJ, values correspond to experiments performed at pH 5.8 because at this pH the overall measured expression was higher. The constitutive gfp fusion (pFPV25.1) varied less than 10% between the conditions tested.