Figure 3.

A, the C. burnetii NAD biosynthetic pathway. B, disruption of nadB alters the level of de novo NAD biosynthetic pathway metabolites. Red, complemented nadB mutant; green, nadB mutant; blue, WT C. burnetii NMII. *, p < 0.05; **, p < 0.01; ***, p < 0.001 (BH-adjusted t test). Fold difference is presented as log₂ scale. C, disruption of nadB reduces the abundance of NAD-containing metabolites. NAD, NADH, and NADP were all significantly reduced in the nadB mutant compared with WT C. burnetii and the complemented nadB mutant. Metabolites were identified using LC/MS, data were median-normalized, and metabolites were identified by reference to authentic standards. *, p < 0.05; **, p < 0.01; ***, p < 0.001 (BH-adjusted t test). Fold difference is presented as log₂ scale.