FIG. 4.

Feedback derepression in a Δfis strain. (A) Promoter activities and ATP and ppGpp concentrations in wild-type and Δfis strains grown in MOPS medium supplemented with 0.4% glucose, 20 amino acids (80 μg/ml), 10 μg of thiamine/ml, and 1 mM KH₂PO₄ were measured as described in the legends for Fig. 2 and 3. (B) Cultures were grown as described in the legend for panel A but in the absence of amino acids. The growth rates of the wild-type and mutant strains were 1.71 and 1.58 doublings/hour, respectively, in panel A and 1.15 and 0.98 doublings/hour, respectively, in panel B.