FIG. 2.
Regulation of V. cholerae ryhB by iron and Fur. The activity of a hutA-lacZ (pAML20) and a ryhB-lacZ (pAML23) transcriptional fusion in high- and low-iron conditions was measured in the wild-type (O395) and the fur mutant (ARM573) strain backgrounds. Bacterial cultures were grown to mid-log phase in iron-replete media (plus FeSO4; high iron) or in iron-depleted media (plus EDDA; low iron), and β-galactosidase activity was measured as described in Materials and Methods. The data represent the averages of three independent experiments. Standard deviations are indicated by the error bars.