Figure 1
Evaluation of thermodynamic stabilities of FADH− in (6–4)PP-repairing proteins by the xanthine/xanthine oxidase (X/XO) method. (a) The oxidation of X to uric acid by XO supplies electrons to FAD and a reference dye Safranin T via a redox mediator methylviologen. The structural model was taken from the reported crystal structure of At64 (PDB: 3FY4)32. (b) The X/XO reaction reduced fully oxidized FADox to two-electron reduced anionic FADH− without accumulating one-electron reduced FADH·. (c) Midpoint potentials of the FADox/FADH− redox pair in (6–4)PP-repairing proteins were ~ − 290 mV vs. SHE. The value was considerably lower than those reported for CPD PL derived from Synechococcus elongatus (SePhrA), formerly called Anacystis nidulans CPD PL11,24 and for the solution FAD (aq) state33. Error bars for our samples reflect the standard deviation for n = 3.
