TABLE 3.
Effect of glnL* alleles on the expression of the nitrogen-regulated glnK promoter under nitrogen-rich conditions in a wild-type glnD background
| Straind | Relevant genotypeb | β-galactosidase activitya on GNGIn Trp + 5x CAAc |
|---|---|---|
| YMC10φ | Wild type | 0 (1) |
| BKcφ | ΔglnB Δmdl-glnK::Camr | 2,100 (1) |
| L*(I12F)φ | glnL (I12F) | 130 |
| L*(L16R)φ | glnL (L16R) | 1,470 |
| L*(L83P)φ | glnL (L83P) | 910 |
| L*(E107K)φ | glnL (E107K) | 1,980 |
| L*(R116G)φ | glnL (R116G) | 600 |
| L*(R116C)φ | glnL (R116C) | 200 |
| L*(L185P)φ | glnL (L185P) | 1,080 |
| L*(G187R)φ | glnL (G187R) | 900 |
| L*(P188R)φ | glnL (P188R) | 190 |
| YMC10φ | Wild type | 0 (1) |
| BKgφ | ΔglnB ΩGmr ΔglnK1 | 1,790 (1) |
| Lφ | ΔglnL2001 | 140 |
| L*(A35V)φ | glnL (A35V) | 110 |
| L*(R115C)φ | glnL (R115C) | 100 |
| L*(E120K)φ | glnL (E120K) | 300 |
| L*(L122P)φ | glnL (L122P) | 2,220 |
| L*(A129T)φ | glnL (A129T) | 540 |
| L*(A138V)φ | glnL (A138V) | 470 |
| L*(G150S)φ | glnL (G150S) | 50 |
| L*(L154R)φ | glnL (L154R) | 1,680 |
| L*(G192D)φ | glnL (G192D) | 470 |
| YMC10φ | Wild type | 0 |
| BKgφ | ΔglnB ΩGmr ΔglnK1 | 1,650 |
| BKgNφ | ΔglnB ΩGmr ΔglnK1 nac::Camr | 1,680 |
| L*(D225V)φ | glnL (D225V) | 1,990 |
| L*(S227N)φ | glnL (S227N) | 1,240 |
| L*(S227R)φ | glnL (S227R) | 1,880 |
| L*(S227I)φ | glnL (S227I) | 1,950 |
| L*(L228R)φ | glnL (L228R) | 2,010 |
| L*(Δ267-270)φ | glnL (Δ267-270) | 840 |
| L*(Y302N)φ | glnL (Y302N) | 1,350 |
| L*(P303L)φ | glnL (P303L) | 720 |
| L*(P303T)φ | glnL (P303T) | 1,660 |
β-Galactosidase activities are given in Miller units and are the average for duplicate cultures except where indicated by the number of cultures in parentheses. Results from duplicate cultures differed by <10%. Cultures were grown overnight in the indicated medium, diluted to an optical density at 600 nm of 0.02 and grown at 30°C to an optical density of 0.5.
In addition to the genotype shown, all strains contain trpDC700::putPA1303 [Kanr glnKp-lac], which is a fusion of the lacZYA operon to the nitrogen-regulated glnK promoter.
The medium used was GNGln Trp + 5x CAA (glucose-ammonia-glutamine-tryptophan plus Casamino Acids) and contained kanamycin. Glucose was present at 0.4% (wt/vol), ammonia and glutamine were present at 0.2% (wt/vol), tryptophan was present at 0.04 mg/ml, and 5× casein hydrolysate was present at 0.5% (wt/vol).
The breaks in the table indicate experiments performed on separate days.