Kinetic studies of KdsB with Kdo or Kdo-N3 as substrate. Specific activity of KdsB with Kdo (blue curve) or Kdo-N3 (red curve) as the sugar substrate with saturating CTP. Kinetic parameters, generated by a fit to the Michaelis–Menten equation, are displayed below the curves. Shaded areas, 95% confidence interval for the fit. The data show a similar kcat for each sugar, whereas the Km increased noticeably for Kdo-N3. Error bars, S.E. Kinetic parameters are reported ± 95% confidence interval. The data were obtained in two independent experiments done in biological triplicates.