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Figure 1 | BMC Microbiology

Figure 1

From: A new suite of tnaA mutants suggests that Escherichia coli tryptophanase is regulated by intracellular sequestration and by occlusion of its active site

Figure 1

Indole is produced when TnaA becomes diffuse. E. coli cells (GL619) expressing TnaA-sfGFP from the constitutive tufA promoter were grown in M9 minimal medium supplemented with 1% casamino acids and 0.5 mM tryptophan. A. Cell growth (OD600). B. TnaA-sfGFP localization at different times. GFP fluorescence and phase contrast images are overlaid. The percentage of the population that has a polar or midcell focus is indicated below each panel; 50–100 cells were examined for each sample. C. TnaA-sfGFP focus formation (squares) plotted against amount of indole produced (triangles). The percentage of cells with TnaA-sfGFP foci are plotted from the data in B. Three independent cultures were assayed for indole production, and the mean ± standard deviation is presented.

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