Comments |
Requires Mg2+. This enzyme, originally isolated from the bacterium Azotobacter vinelandii, is a complex of two components (namely dinitrogen reductase and dinitrogenase). Dinitrogen reductase is a [4Fe-4S] protein, which, in the presence of ATP, transfers an electron from ferredoxin to the dinitrogenase component. Dinitrogenase is a vanadium-iron protein that reduces dinitrogen to two molecules of ammonia in three successive two-electron reductions via diazine and hydrazine. Compared with molybdenum-depedent nitrogenase (EC 1.18.6.1), this enzyme produces more dihydrogen and consumes more ATP per dinitrogen molecule being reduced. Unlike EC 1.18.6.1, this enzyme can also use CO as substrate, producing ethylene, ethane and propane [7,9]. |