TABLE 1.

Kinetic parameters of TcpXHa

SubstrateKm (μM)kcat (s−1)kcat/Km (M−1 s−1)
FMNNADHb25.0 ± 2.5570.2 ± 14.32.3 × 107
NADHFMNd64.8 ± 6.6559.9 ± 16.98.7 × 106
FADNADHb10.8 ± 1.276.8 ± 2.67.1 × 106
NADHFADc244.1 ± 48.894.5 ± 7.84.0 × 105
  • a Experiments were done in 60 mM KPi (pH 6.7) at 25°C. Values are averages of three measurements with standard deviations. No activities were detected for riboflavin and NADPH.

  • b Determined with fixed NADH concentration at 300 μM.

  • c Determined with fixed FAD concentration at 20 μM.

  • d Determined with fixed FMN concentration at 50 μM.