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 nif genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The primary enzyme encoded by the nif genes is the nitrogenase complex which is in charge of converting atmospheric nitrogen (N 2) to other nitrogen forms such as ammonia which the organism can use for various purposes.
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]
The very last step of nitrate reductase inactivation is the binding of the 14-3-3 adapter protein, which is initiated by the presence of Mg 2+ and Ca 2+. [14] Higher plants and some algae post-translationally regulate NR by phosphorylation of serine residues and subsequent binding of a 14-3-3 protein. [15]
Base pairing: Two base pairs are produced by four nucleotide monomers, nucleobases are in blue. Guanine (G) is paired with cytosine (C) via three hydrogen bonds, in red. Adenine (A) is paired with uracil (U) via two hydrogen bonds, in red. Purine nucleobases are fused-ring molecules. Pyrimidine nucleobases are simple ring molecules.
They fix nitrogen from dinitrogen (N 2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis. [2] Nitrogenase is inactivated by oxygen, so the heterocyst must create a microanaerobic environment. The heterocysts' unique structure and physiology require a global change in gene ...