TABLE 4.
Effects of narL and narP null alleles on expression of the lacZ gene from O3-lac O1 substitution constructsa
| Construct | Genotype
|
LacZ sp actb with:
|
Repression with:
|
||||
|---|---|---|---|---|---|---|---|
| narL | narP | No addition | NO3− | NO2− | NO3− | NO2− | |
| O3-lac O1-nirB | + | + | 3,390 | 30 | 360 | 110 | 9.4 |
| + | − | 3,350 | 39 | 520 | 86 | 6.4 | |
| − | + | 3,470 | 680 | 1,010 | 5.1 | 3.4 | |
| − | − | 3,270 | 2,330 | 2,860 | 1.4 | 1.1 | |
| O3-lac O1-napF | + | + | 1,150 | 85 | 290 | 14 | 4.0 |
| + | − | 1,160 | 100 | 650 | 12 | 1.8 | |
| − | + | 1,210 | 140 | 170 | 8.6 | 7.1 | |
| − | − | 1,170 | 760 | 1,050 | 1.5 | 1.1 | |
a
Specific activity is indicated in Miller units.
b
Strains were cultured overnight in MOPS defined medium with limiting glucose. All carry λRS45-derived prophages.