FIG. 1.

Effect of hemin addition on hemZ reporter activity. (A) Wild-type expression of the hemZ reporter under semiaerobic conditions in the presence of various concentrations of exogenous hemin is shown. (B) Wild-type expression of hem reporters under semiaerobic conditions in the presence and absence of 30 μmol hemin is shown. Values presented for each reporter are the means and standard deviations of at least three independent assays and are reported as micromoles of ONPG hydrolyzed per minute per milligram of cellular protein.