TABLE 2.
Effects of mutations on transport of ferripyoverdine, pyoverdine synthesis, and FpvA-mediated signaling
| Strain or mutationa | Pyoverdine-dependent iron transportb (mean fmol/ml ± SD) | Pyoverdine synthesisc (mean μmol/ml ± SD) | Signalingd (mean U ± SD) |
|---|---|---|---|
| PAO | 22.52 ± 1.74 | 103.4 ± 12.1 | 527.3 ± 49.0 |
| FpvA+ | 20.81 ± 2.30 | 93.3 ± 2.3 | 482.2 ± 35.0 |
| FpvA− | 3.27 ± 0.34 | 22.3 ± 7.3 | 177.7 ± 28.4 |
| E4 | 20.72 ± 1.97 | 35.7 ± 12.9 | 113.7 ± 31.4 |
| R21 | 21.33 ± 2.21 | 23.7 ± 6.4 | 78.4 ± 23.8 |
| I25 | 19.64 ± 4.49 | 22.3 ± 6.5 | 115.5 ± 45.0 |
| L46 | 19.56 ± 4.14 | 13.3 ± 4.6 | 160.0 ± 35.6 |
| L55 | 23.19 ± 1.01 | 6.7 ± 3.9 | 111.3 ± 21.1 |
| T90 | 7.05 ± 0.73 | 24.3 ± 3.9 | 382.5 ± 30.6 |
| N172 | 3.66 ± 0.40 | 32.7 ± 22.2 | NDe |
| N224 | 4.48 ± 0.61 | 11.8 ± 0.6 | 148.2 ± 16.9 |
| K228 | 3.90 ± 0.29 | 12.3 ± 4.3 | ND |
| H237 | 13.67 ± 1.57 | 31.4 ± 9.8 | ND |
| L297 | 17.69 ± 1.15 | 22.4 ± 7.8 | 185.2 ± 66.2 |
| G318 | 3.62 ± 0.20 | 14.9 ± 10.7 | 130.1 ± 39.0 |
| E360 | 8.56 ± 0.24 | 17.7 ± 5.2 | ND |
| H375 | 3.54 ± 0.21 | 17.7 ± 8.5 | 151.1 ± 35.4 |
| N378 | 3.83 ± 0.33 | 14.9 ± 8.9 | ND |
| V401 | 6.47 ± 0.51 | 39.9 ± 21.2 | ND |
| I416 | 3.75 ± 0.24 | 27.2 ± 12.9 | ND |
| L431 | 12.76 ± 1.34 | 31.5 ± 18.7 | ND |
| S446 | 4.24 ± 0.19 | 26.7 ± 3.9 | 109.6 ± 51.7 |
| P475 | 17.03 ± 2.94 | 23.7 ± 7.2 | 101.8 ± 28.8 |
| D480 | 5.97 ± 0.34 | 25.5 ± 4.9 | ND |
| D510 | 3.43 ± 0.28 | 80.5 ± 10.1 | 637.3 ± 37.1 |
| Y511 | 4.25 ± 0.65 | 68.4 ± 10.1 | 611.9 ± 76.0 |
| E566 | 6.96 ± 0.64 | 26.5 ± 6.2 | ND |
| Q571 | 4.00 ± 0.29 | 19.6 ± 9.3 | ND |
| G576 | 3.56 ± 0.22 | 31.9 ± 7.0 | ND |
| E594 | 5.01 ± 1.71 | 78.2 ± 20.8 | 542.5 ± 90.3 |
| I653 | 9.75 ± 0.95 | 43.3 ± 11.9 | ND |
| L685 | 17.80 ± 3.28 | 21.2 ± 3.8 | 241.2 ± 61.4 |
| D743 | 7.32 ± 1.30 | 23.1 ± 8.6 | ND |
| R762 | 3.56 ± 0.31 | 20.3 ± 8.1 | 241.7 ± 65.1 |
Mutations A-12, P257, E294, L564, and A724 resulted in FpvA being undetectable in the outer membrane (Fig 3A and B) and resulted in pyoverdine-dependent iron transport at levels indistinguishable from that of the FpvA mutant (data not shown); pyoverdine production and signaling were not measured for these mutants.
In pmol of 55Fe taken up in 30 minutes per ml of bacteria. All values are the means of at least three experiments with standard deviations shown.
In μmol of pyoverdine per ml of culture. All values are the means of at least three experiments with standard deviations shown.
In units of β-galactosidase expressed from a pvdE::lacZ fusion construct. All values are the means of at least three experiments with standard deviations shown.
ND, not determined.