Michaelis–Menten kinetics of StyB from Rhodococcus opacus 1CP. The purified reductase was applied to enzyme assays as described in “Materials and methods” section. By varying the concentration of one of the substrates (NADH left panel or FAD right panel) apparent V
MAX and K
M-values were obtained by fitting initial velocities to the Michaelis–Menten equation. Data points shown are mean values of at least triplicate measurements and standard errors for each data-set are shown as red bars.