FIG. 4.

ModE does not regulate moa expression from the distal promoter. The plasmids were present in the strains as indicated. Cells were grown under anaerobic conditions at 37°C in LB medium with 125 μg of ampicillin/ml. Where indicated, sodium molybdate was added at a final concentration of 10 mM. β-Galactosidase activity is expressed in Miller units (24).