Extended Data Fig. 3: Biochemical characterization of the ketoreductase PdxG.
a, In vitro reaction of 3 μM PdxG with 2 mM NADPH using 600 μM 5 as the substrate. 60% conversion from 5 to 6 was observed within 20 min. b, Kinetic analysis of PdxG-catalysed reduction of 5. Reaction mixtures containing 3 μM PdxG, 2 mM NADPH and different concentrations of 5 (10 μM to 1.2 mM) were incubated at 30 °C for 20 min. Error bars indicate s.d. of three independent replicates. c, Formation of 10 from 6 in the presence of 2 mM NADPH can be observed both with and without PdxG. Compound 6 was obtained from chemical reduction of 5 with NaBH4. Since 10 can be formed in the presence of only NADPH, we conclude NADPH can nonenzymatically reduce the QM to 10, which accounts for the result in Fig. 1f.
