FIGURE 6.

Schematic diagram of KEGG-derived phenylalanine, tyrosine and tryptophan biosynthesis pathways. Boxes indicate key products/intermediates. Briefly, over seven metabolic steps, the shikimate pathway converts phosphoenolpyruvate and erythrose 4-phosphate to shikimate which is then converted to chorismate, the precursor of aromatic amino acids. Red arrows indicate reactions associated with predicted conditionally essential genes in M9 minimal medium while gray arrows indicate reactions in which the associated genes are non-essential. Associated genes are listed next to their corresponding reactions: essential genes in black font; non-essential genes in gray font.