FIG 5 .

Inactivation of HemX reduces GtrR abundance in heme-deficient strains. (A) The abundance of GtrR was measured by LC-MRM-MS/MS in multiple S. aureus strains. The data are the average from a single experiment performed in biological triplicate with standard deviation shown. Statistical significance was determined using a one-way ANOVA with Dunnett’s correction for multiple comparisons, comparing GtrR abundance for each strain relative to WT. *, P < 0.05. (B) Uroporphyrinogen III (detected as uroporphyin III), coproporphyrin III, coproheme III, and heme were quantified by LC-qTOF-MS. Graphed is the fold change of metabolite abundance in each mutant relative to the WT from a single experiment performed in biological triplicate with standard error of the mean shown.