FIGURE 9.

GrlR represses the expression of LEE1 and LEE2 operons in the absence of H-NS, GrlA and Ler. Expression of LEE1-cat (black bars) and LEE2-cat (white bars) fusions was analyzed in panel (A) WT Escherichia coli MC4100 and (B) MC4100 Δhns (JPMC1) strains, carrying the empty vector pMPMT-3 or its derivatives pT3GrlR, pTEPGrlA1 and pT3GrlRA grown in 50 ml of Dulbecco’s modified Eagle’s medium (DMEM) with shaking at 37°C. Specific chloramphenicol acetyltransferase (CAT) activity was determined from samples collected from cultures grown in DMEM at an OD₆₀₀ of 1. Values are an average of 3 independent experiments performed in duplicate. Error bars indicate standard deviations. Statistically different values are indicated (*p-value < 0.1; ^****p-value < 0.0001).