Oxidoreductases;
Acting on iron-sulfur proteins as donors;
With dinitrogen as acceptor
BRITE hierarchy

ferredoxin:dinitrogen oxidoreductase (ATP-hydrolysing, molybdenum-dependent)

8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O = 8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate [RN:R05185]

R05185;
(other) R00002 R00067 R00153 R02802 R04782 R05496
Reaction

reduced ferredoxin [CPD:C00138];
H+ [CPD:C00080];
N2 [CPD:C00697];
ATP [CPD:C00002];
H2O [CPD:C00001]

Requires Mg2+. The enzyme is a complex of two components (namely dinitrogen reductase and dinitrogenase). Dinitrogen reductase is a [4Fe-4S] protein, which, in the presence of two molecules of ATP, transfers an electron from ferredoxin to the dinitrogenase component. Dinitrogenase is a molybdenum-iron protein that reduces dinitrogen to two molecules of ammonia in three successive two-electron reductions via diazene and hydrazine. The reduction is initiated by formation of hydrogen in stoichiometric amounts [2]. Acetylene is reduced 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. Ferredoxin may be replaced by flavodoxin [see EC 1.19.6.1 nitrogenase (flavodoxin)]. The enzyme does not reduce CO (cf. EC 1.18.6.2, vanadium-dependent nitrogenase).

EC 1.18.6.1 created 1978 as EC 1.18.2.1, transferred 1984 to EC 1.18.6.1, modified 2005, modified 2018

1  [PMID:4390523]

2  [PMID:3200830]

3  [PMID:15382920]

4  [PMID:10852721]