FIG. 8.

UV-visible assays of the reduction of 50 μM TCBQ by 1 mM NADPH at 25°C in 50 mM potassium phosphate, pH 8.0, in the absence and presence of PcpD monitored by observing the change in absorbance at 340 nm. The upper trace shows the rate of the nonenzymatic reaction; the middle and lower traces show the rate in the presence of His₁₂-tagged PcpD at 37 and 74 μg/ml.