FIGURE 1: Carbon and phosphate starvations stimulate the expression of E. coli aphA. (A) Schematic overview showing the promoter region of E. coli aphA gene, with the start and stop codons and potential four promoter sequences marked (in bars). (B) Sequence annotation of the potential promoter region of E. coli aphA. Text highlighted in blue is the CytR box; SD, Shine-Dalgarno sequence. (C) Schematic overview showing the promoter regions of aphA, which were transcriptionally fused to a lacZ reporter gene in the plasmid pGH254 [10]. (D, E, F) Beta-galactosidase assays of the various transcriptional reporters during starvations of carbon, phosphate, and amino acid. Time zero indicates the time point right before the downshift of cells. Three biological replicates were performed, and the average and standard deviations are shown. The significance of unpaired t-test is indicated by the symbols ** (p-value < 0.01), *** (p-value < 0.001), and **** (p-value < 0.0001).