Figure 8
From: Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12
Search for inducer candidates for derepression of the yiaK promoter by PlaR. 2.5 uM of Purified PlaR was mixed with 0.5 pM of a DNA probe corresponding to the promoter sequence of yiaK gene. The yiaK promoter formed stable complexes with PlaR as shown in Fig. 3. Possible inducers affecting the yiaK promoter-PlaR complex formation, a variety of carbon sources were examined using the gel shift assay system. (Panel a) Eight species of carbon metabolite were tested at 10 mM concentrations. (Panel b) influence of two effective metabolites, ascorbate and D-galacturonate, was examined in details by increasing concentrations. (b) Ascorbate or D-galacturonate (mM) was added: lane 3, 1; lane 4, 2.5; lane 5, 5; lane 6, 10; lane 7, 25, respectively. Filled arrow indicates PlaR-yiaK promoter probe complex and open arrow indicates free probe.
