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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 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.
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] Column K is that of Koltun's patent. [4] Column J is the color scheme used by the molecular visualizer Jmol. [9] Column R is the scheme used by Rasmol; when two colors are shown, the second one is valid for versions 2.7.3 and later. [9] [10] Column P consists of the colors in the PubChem database managed by the United States National ...
The Cu−S 1 contact is shorter (207 pm) than Cu−S 2 (282 pm). The elongated Cu−S 2 bonding destabilizes the Cu(II) form and increases the redox potential of the protein. The blue color (597 nm peak absorption) is due to the Cu−S 1 bond where S(pπ) to Cu(d x 2 −y 2) charge transfer occurs. [21]
H 2 1sσ* antibonding molecular orbital. In theoretical chemistry, an antibonding orbital is a type of molecular orbital that weakens the chemical bond between two atoms and helps to raise the energy of the molecule relative to the separated atoms. Such an orbital has one or more nodes in the bonding region between the nuclei.
The color of chemicals is a physical property of chemicals that in most cases comes from the excitation of electrons due to an absorption of energy performed by the chemical. The study of chemical structure by means of energy absorption and release is generally referred to as spectroscopy .