FIG. 2.

(A) GRDC of the leuV(−50 +10) promoter and its mutants. β-Galactosidase (β-gal) activities of promoter–trp-lacZ fusions are plotted against growth rate expressed as doublings per hour. Each datum point represents the average of at least three independent experiments. The slopes determined for the different promoters using Sigma Plot linear regression analyses were as follows: leuV, 0.75; T45 mutant, −3; D mutant, −2; and A7 mutant, 0.73. (B) GRDC of leuV(−107 +55) promoter and D mutant (residues −50 to +11) in relA spoT mutant strain and control strain MG1655.