Fig 2.

LVS mutants with mutations in migR, trmE, and cphA have reduced ppGpp levels. Radiolabeled phosphate was added to each of the F. tularensis strains for 1 h, and cell lysates were run on a TLC plate to visualize ppGpp. A graphical representation of ppGpp radioactive counts after being normalized to LVS ppGpp counts, which were arbitrarily set to 100, is shown. All mutants had decreased ppGpp accumulation compared to that of wild-type strain LVS (P < 0.001). Complemented strains (designated LVS migRc, LVS trmEc, and LVS cphAc) produced significantly increased amounts of ppGpp compared to their mutant counterparts.