... stabilized by the wild-typeenzyme ([SQ] ¼ 22.4% as determined by photoreductionexperiments) are known. Thus, by simultaneously solvingthis Nernst derived two-equation system, the reductionpotentials ... of the three FMN redox forms bytyrosine 94 and tryptophan 57 in flavodoxin from Anabaena andits influence on the reduction potentials. Biochemistry 36, 14334–14344.22. Pueyo, J.J., Go´mez-Moreno, ... determines its reduction potentialwithin the protein environment [19–21]. For many years, noreduction potentials for FNR mutants were reported [4,15],and only recently have we been able to achieve...