Fig. 3

Suppressor mutations predicted to reduce expression of wild-type CsrA. Fold siderophore (blue bars) and fold luminescence (yellow bars) relative to wild-type ES114 are shown for gacA mutants and suppressors, where error bars indicate 95 % confidence intervals of 5–8 replicates. Growth on minimal media agar supplemented with glycerol or N-acetylglucosamine is designated for each strain by “+” for growth and “-“for no growth. Growth yield (OD₆₀₀) is expressed as a percent of wildtype grown overnight in SWT. For each suppressor the csrA mutation precedes the row identifying whether a promoter, Shine-Dalgarno (SD), alternative start codon, or silent mutation subject to codon bias [52] is the predicted cause of decreased expression. The names of the strains are color coded by genetic background as described in Table 1