TABLE 2.

Activities of ProU systems incorporating wild-type and FlAsH-tagged ProW

Relevant genotypeaProW variantGlycine betaine uptake rate (nmol min−1 mg protein−1)b
proU+ (proVWX+)ProW28.2 ± 0.5
ΔproWNone0.08 ± 0.08
ΔproW pBAD24None0.05 ± 0.09c
ΔproW pTR3ProW10.8 ± 0.1c
ΔproW pTR4MACCPGCC-ProW9.1 ± 0.8c
  • a The host bacteria either were proU+ (WG170) or harbored an in-frame proW deletion (WG350 ΔproW859::FRT).

  • b Bacteria were cultivated and transport assays were performed as described in Materials and Methods. Cells were grown under osmotic stress conditions (0.3 M NaCl) to induce proU transcription.

  • c Cells were induced with 1 mM arabinose for one generation (∼2.5 h).