Table 2.

Transcription from the glpA1, glpK, and tnaApromoter regions based on a β-galactosidase reporter gene

Medium and strainSp act of β-galactosidase (mU·mg−1)awith the following promoterb:
P1glpA1(310 bp)P2glpK(354 bp)PtnaA(321 bp)P2rrnA(551 bp)Vector (none)
Gly MM
    H26 (parent)310 ± 516 ± 2ND260 ± 108.1 ± 0.1
    ΔglpKmutantNo growthNo growthNo growthNo growthNo growth
    ΔglpA1mutantNo growthNo growthNo growthNo growthNo growth
    ΔglpRmutant300 ± 718 ± 2ND260 ± 38.7 ± 0.9
Glu MM
    H26 (parent)38 ± 0.122 ± 0.7ND250 ± 77.3 ± 0.9
    ΔglpKmutant30 ± 125 ± 2ND250 ± 86.5 ± 0.7
    ΔglpA1mutant35 ± 321 ± 1ND260 ± 39.2 ± 1
    ΔglpRmutant36 ± 0.523 ± 0.6ND250 ± 48.3 ± 0.9
Gly Glu MM
    H26 (parent)280 ± 814 ± 2ND260 ± 28.1 ± 0.05
    ΔglpKmutant28 ± 222 ± 3ND250 ± 58.3 ± 0.6
    ΔglpA1mutant270 ± 918 ± 0.5ND240 ± 67.3 ± 0.5
    ΔglpRmutant270 ± 819 ± 1ND250 ± 78.0 ± 0.5
Suc MM (H26 [parent])NDND38 ± 6260 ± 208.0 ± 0.08
Suc Trp MM (H26 [parent])NDND1,700 ± 50230 ± 307.4 ± 0.07
  • a Determined from the lysates of cells grown to log phase in minimal medium (MM) as indicated. No growth, mutant strains that did not grow on Gly MM; ND, not determined. Experiments were performed in biological triplicate, and the means ± standard deviations were calculated.

  • b The parental strain H26 and the ΔglpK, ΔglpA1, and ΔglpRmutant strains were transformed with a plasmid carrying the promoter region of glpA1(P1glpA1) or glpK(P2glpK) transcriptionally fused to the β-galactosidase bgaHreporter gene. The tryptophan-inducible promoter PtnaAand the strong promoter P2rrnAwere included for comparison. Promoter fusions included the start codon and genomic region immediately upstream of each target gene. The length of the promoter fusion is given in parentheses after the promoter designation. Plasmid vector pJAM2715, containing only a Shine-Dalgarno sequence upstream of bgaH, served as a negative control.