FIG. 5.

Role of HcaR in expression off the hca promoter. Promoter activity was measured by β-galactosidase activity (Miller units) by using strains with the chromosomal insertion hcaE::lacZ. Cultures were grown on succinate with or without the addition of 1 mM caffeate, p-coumarate, or ferulate. Not shown are the LacZ levels for ADP8110 cells grown at the expense of hydroxycinnamates in the absence of succinate: 928 Miller units with p-coumarate alone, 899 Miller units with caffeate alone, and 825 Miller units with ferulate alone. Data are averages based on three independent trials; error bars indicate standard deviations.