FIG. 5.

Genomic organization of l-arginine biosynthesis in L. pneumophila. The ORF encoding ArgR, lpg490, is divergent from a region spanning lpg0491 to lpg0496, in which the genes exhibit strong negative regulation by ArgR (A). lpg0491 to -0493 are predicted to encode an amino acid ABC transporter, and lpg0494 to -0496 are predicted to encode the final steps of l-arginine biosynthesis (A). The biosynthetic pathway for the conversion of l-glutamate to l-arginine is shown with the L. pneumophila ORF associated with each enzymatic step, if present, in parentheses (B). The ΔargR/WT log₂ ratio is shown at each step below the ORF for the exponential and postexponential phases (B).