Search results
Results from the WOW.Com Content Network
The Fe protein, the dinitrogenase reductase or NifH, is a dimer of identical subunits which contains one [Fe 4 S 4] cluster and has a mass of approximately 60-64kDa. [2] The function of the Fe protein is to transfer electrons from a reducing agent, such as ferredoxin or flavodoxin to the nitrogenase protein.
FeMoco (FeMo cofactor) is the primary cofactor of nitrogenase. Nitrogenase is the enzyme that catalyzes the conversion of atmospheric nitrogen molecules N 2 into ammonia (NH 3) through the process known as nitrogen fixation. Because it contains iron and molybdenum, the cofactor is called FeMoco. Its stoichiometry is Fe 7 MoS 9 C.
The nitrogenase holoenzyme of A. vinelandii has been characterised by X-ray crystallography in both ADP tetrafluoroaluminate-bound [5] and MgATP-bound [6] states. The enzyme possesses molybdenum iron - sulfido cluster cofactors ( FeMoco ) as active sites , each bearing two pseudocubic iron-sulfido structures.
Their formal oxidation states may vary from [Fe 3 S 4] + (all-Fe 3+ form) to [Fe 3 S 4] 2− (all-Fe 2+ form). In a number of iron–sulfur proteins, the [Fe 4 S 4] cluster can be reversibly converted by oxidation and loss of one iron ion to a [Fe 3 S 4] cluster. E.g., the inactive form of aconitase possesses an [Fe 3 S 4] and is activated by ...
Nitrogenase is thought to have evolved sometime between 1.5-2.2 billion years ago (Ga), [38] [39] although some isotopic support showing nitrogenase evolution as early as around 3.2 Ga. [40] Nitrogenase appears to have evolved from maturase-like proteins, although the function of the preceding protein is currently unknown. [41]
3 Ca + N 2 → Ca 3 N 2 3 Mg + 2 NH 3 → Mg 3 N 2 + 3 H 2 (at 900 °C) 3 Zn(NH 2) 2 → Zn 3 N 2 + 4 NH 3. Many variants on these processes are possible. The most ionic of these nitrides are those of the alkali metals and alkaline earth metals, Li 3 N (Na, K, Rb, and Cs do not form stable nitrides for steric reasons) and M 3 N 2 (M = Be, Mg ...
The iron in cytochromes usually exists in a ferrous (Fe 2+) and a ferric (Fe 3+) state with a ferroxo (Fe 4+) state found in catalytic intermediates. [1] Cytochromes are, thus, capable of performing electron transfer reactions and catalysis by reduction or oxidation of their heme iron. The cellular location of cytochromes depends on their function.
The dinitrogen complex trans-[IrCl(N 2)(PPh 3) 2] is made by treating Vaska's complex with aromatic acyl azides. It has a planar geometry. [7] The first preparation of a metal-dinitrogen complex using dinitrogen was reported in 1967 by Yamamoto and coworkers. They obtained [Co(H)(N 2)(PPh 3) 3] by reduction of Co(acac) 3 with AlEt 2 OEt under ...