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ENZYME entry: EC

Accepted Name
nitrogenase (flavodoxin)
Reaction catalysed
16 ATP + 16 H2O + N2 + 4 reduced [flavodoxin] <=> 16 ADP + 18 H(+) + H2 + 2 NH4(+) + 4 oxidized [flavodoxin] + 16 phosphate
  • Composed of two components, dinitrogen reductase and dinitrogenase, that can be separated but are both required for nitrogenase activity.
  • Dinitrogen reductase is a [4Fe-4S] protein, which, at the expense of ATP, transfers electrons from a dedicated flavodoxin to dinitrogenase.
  • Dinitrogenase is a protein complex that contains either a molybdenum- iron cofactor, a vanadium-iron cofactor, or an iron-iron cofactor, that reduces dinitrogen in three succesive two-electron reductions from nitrogen to diimine to hydrazine to two molecules of ammonia.
  • The reduction is initiated by formation of hydrogen.
  • The enzyme can also reduce acetylene to ethylene (but only very slowly to ethane), azide to nitrogen and ammonia, and cyanide to methane and ammonia.
  • In the absence of a suitable substrate, hydrogen is slowly formed.
  • Some enzymes utilize ferredoxin rather than flavodoxin as the electron donor (see EC
PRIAM enzyme-specific profiles1.19.6.1
KEGG Ligand Database for Enzyme Nomenclature1.19.6.1
IUBMB Enzyme Nomenclature1.19.6.1
MEDLINEFind literature relating to
Rhea expert-curated reactions1.19.6.1

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