1.12.1.2 4Fe-4S-center presence of a 4Fe-4S-center in addition to the active site iron 724910 1.12.1.2 ATP 30% stimulation 439699 1.12.1.2 benzyl viologen oxidized and reduced 439633, 656298 1.12.1.2 Ferredoxin the hydrogenase requires the presence of both electron carriers, NADH and reduced ferredoxin, synergistically for catalysis of H2 production 712281 1.12.1.2 flavin 1 molecule of FMN per enzyme molecule 439703 1.12.1.2 flavin 2 molecules of FMN per enzyme molecule 439710 1.12.1.2 flavin flavoprotein 439699, 439703, 439710 1.12.1.2 flavin only when FMN or riboflavin are added in combination with Mg2+ or Ni2+, NAD-reducing system is activated 439701 1.12.1.2 FMN - 712281 1.12.1.2 FMN 1 FMN molecule per enzyme molecule 439703