TABLE 3.
Effect of deletions and amino acid substitutions in ResE on ResDE-dependent gene expression under aerobic and anaerobic conditions
| Plasmid | Relevant characteristic (subdomain)b | β-Galactosidase activity (Miller units)a
|
|||
|---|---|---|---|---|---|
|
nasD-lacZ
|
hmp-lacZ
|
||||
| +O2 | −O2 | +O2 | −O2 | ||
| pMMN525 | Full | 1.0 ± 0.3 | 163 ± 21 | 9.0 ± 0.5 | 1965 ± 354 |
| pMMN536 | Full (HAMP A207V) | 1.0 ± 0.0 | 122 ± 6.0 | 7.0 ± 2.0 | 1834 ± 185 |
| pMMN537 | Full (HAMP E226D) | 2.5 ± 0.5 | 354 ± 34 | 17 ± 2.0 | 2507 ± 211 |
| pMMN544 | Full (− HAMP) | 8.0 ± 1.7 | 259 ± 56 | 41 ± 5.0 | 2730 ± 118 |
| pMMN559 | Full (− PAS) | 1.5 ± 0.3 | 3.0 ± 0.0 | 12 ± 6.0 | 110 ± 17 |
| pMMN563 | Full | 1.0 ± 0.2 | 177 ± 5.0 | 12 ± 4.0 | 1856 ± 302 |
| pMMN534 | Cytoplasmic (+ TM2) | 1.0 ± 0.0 | 37 ± 7.0 | 10 ± 3.0 | 654 ± 26 |
| pMMN565 | Cytoplasmic | 1.0 ± 0.3 | 39 ± 6.0 | 8.0 ± 0.5 | 858 ± 167 |
| pMMN564 | Cytoplasmic (− PAS) | 1.0 ± 0.0 | 2.0 ± 0.0 | 6.0 ± 1.0 | 59 ± 2.0 |
| pAB3 | Cytoplasmic (− HAMP) | 1.0 ± 0.0 | 11 ± 1.0 | 6.0 ± 1.5 | 259 ± 33 |
| pAB4 | Cytoplasmic (− HAMP, − PAS) | 1.0 ± 0.0 | 2.0 ± 0.0 | 12 ± 6.0 | 95 ± 18 |
a
Cells were grown in 2× YT supplemented with 1% glucose, 0.2% potassium nitrate, and 1 mM IPTG (0.02 mM IPTG in cells carrying pMMN563). Samples were taken at time intervals for measurement of β-galactosidase activity under aerobic (+O2) and anaerobic (−O2) conditions. The maximal levels of activity are given, and all values are the averages of three to four independent experiments with standard deviations.
b
Full, full-length ResE; +, with the indicated subdomain; −, without the indicated subdomain. Mutations in HAMP are also indicated.