Table 1.
In vivo activation of PhoB proteins by ′PhoR and ′VanS kinases
| Regulator | Kinase† | Bap sp
act*
|
β-galactosidase sp act†
|
||
|---|---|---|---|---|---|
| No arabinose | With arabinose | No arabinose | With arabinose | ||
| PhoBwt | None | 0.3 ± 0.1 | 0.3 ± 0.0 | 6.1 ± 0.2 | 6.5 ± 0.7 |
| PhoBwt | ′PhoR | 0.4 ± 0.1 | 185 ± 3 | 6.4 ± 0.2 | 194 ± 7 |
| PhoBwt | ′VanS | 0.4 ± 0.2 | 0.3 ± 0.0 | 6.1 ± 0.4 | 6.4 ± 0.1 |
| PhoBM17V,E87D | ′PhoR | 1.2 ± 1.5 | 516 ± 36 | 7.5 ± 2.2 | 968 ± 8 |
| PhoBM17V,E87D | ′VanS | 0.4 ± 0.2 | 63.5 ± 1.3 | 5.7 ± 0.5 | 53.1 ± 4.4 |
| PhoBM17V,E87D | ′VanSH164Q | 0.3 ± 0.0 | 0.7 ± 0.2 | 6.7 ± 0.2 | 4.7 ± 0.1 |
| PhoBT97A | ′PhoR | 0.6 ± 0.0 | 174 ± 8 | 6.7 ± 0.1 | 204 ± 10 |
| PhoBT97A | ′VanS | 0.4 ± 0.0 | 125 ± 9 | 6.4 ± 0.3 | 127 ± 7 |
Cells were assayed after growth in 0.06% glycerol Mops 2 mM Pi media without or with arabinose. Bap, bacterial alkaline phosphatase.
*
Specific activity (sp act) units are nanomoles of product formed per minute per cell optical density at 420 nm. Means of triplicate determinations with standard deviations are given.
†
Strains are integrants of BW23316 [like BW23423, except Δ(araBAD)AH37], BW23423, BW23425, or BW23427 with a pSK50 derivative encoding the respective PhoB protein.