Relative activities of selected RpoH_I- and RpoH_II-dependent promoters.

β-galactosidase activity of lacZ operon fusions with selected R. sphaeroides promoter regions monitored in tester strains expressing RpoH_I (black), RpoH_II (grey), or neither proteins. Genes are grouped according to the gene expression profiles displayed in the gene expression experiments: genes whose expressions were affected only by RpoH_I, only by RpoH_II, and by both RpoH_I and RpoH_II. Error bars represents the standard error of the mean from three independent replicates.