Synonyms |
ARA, dinitrogenase, EC 1.18.2.1, Kp2, Mo nitrogenase, Mo-dependent nitrogenase, Mo-Fe nitrogenase, Mo-nitrogenase, MoFe protein, MoFe-protein, molybdenum nitrogenase, molybdenum-containing nitrogenase, molybdenum-iron protein, molybdenum-nitrogenase, More, N2ase, nif, nif1, nif2, nifD, NifDK, NifH, NifH2, nifHDK, nifK, nifM, nitrogenase Fe protein, nitrogenase Fe-protein, nitrogenase FeVco, nitrogenase iron-protein, nitrogenase MoFe protein, nitrogenase MoFe-protein, nitrogenase molybdenum iron protein, nitrogenase molybdenum-iron protein, V-nitrogenase, vanadium nitrogenase, vanadium-nitrogenase, VnfDGK, VnfH |
Comments |
Requires Mg2+. The enzyme is a complex of two components (namely dinitrogen reducatse 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). |