A report on Nitrogenase

Structure of the FeMo cofactor showing the sites of binding to nitrogenase (the amino acids cys and his).
Figure 1: Nitrogenase with key catalytic sites highlighted. There are two sets of catalytic sites within each nitrogenase enzyme.
Figure 2: Nitrogenase with one set of metal clusters magnified. Electrons travel from the Fe-S cluster (yellow) to the P cluster (red), and end at the FeMo-co (orange).
Figure 3: Key catalytic sites within nitrogenase. Atoms are colored by element. Top: Fe-S Cluster Middle: P Cluster Bottom: FeMo-co
Figure 4: Lowe-Thorneley kinetic model for reduction of nitrogen to ammonia by nitrogenase.
Figure 5: Distal vs. alternating mechanistic pathways for nitrogen fixation in nitrogenase.
Figure 6: Amino acid residues of nitrogenase that interact with MgATP during catalysis.

Nitrogenases are enzymes that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria.

- Nitrogenase
Structure of the FeMo cofactor showing the sites of binding to nitrogenase (the amino acids cys and his).

20 related topics with Alpha

Overall
Schematic representation of the nitrogen cycle. Abiotic nitrogen fixation has been omitted.

Nitrogen fixation

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Chemical process by which molecular nitrogen, with a strong triple covalent bond, in the air is converted into ammonia or related nitrogenous compounds, typically in soil or aquatic systems but also in industry.

Chemical process by which molecular nitrogen, with a strong triple covalent bond, in the air is converted into ammonia or related nitrogenous compounds, typically in soil or aquatic systems but also in industry.

Schematic representation of the nitrogen cycle. Abiotic nitrogen fixation has been omitted.
Nodules are visible on this broad bean root
A sectioned alder tree root nodule
Equipment for a study of nitrogen fixation by alpha rays (Fixed Nitrogen Research Laboratory, 1926)
Lightning heats the air around it breaking the bonds of starting the formation of nitrous acid.

Biological nitrogen fixation or diazotrophy is an important microbially mediated process that converts dinitrogen (N2) gas to ammonia (NH3) using the nitrogenase protein complex (Nif).

Leguminous plants used to fertilize an abandoned land

Diazotroph

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Diazotrophs are bacteria and archaea that fix atmospheric nitrogen gas into a more usable form such as ammonia.

Diazotrophs are bacteria and archaea that fix atmospheric nitrogen gas into a more usable form such as ammonia.

Leguminous plants used to fertilize an abandoned land

All diazotrophs contain iron-molybdenum or -vanadium nitrogenase systems.

Cyanobacteria

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Cyanobacteria, also known as Cyanophyta, are a phylum of Gram-negative bacteria that obtain energy via photosynthesis.

Cyanobacteria, also known as Cyanophyta, are a phylum of Gram-negative bacteria that obtain energy via photosynthesis.

Cyanobacteria are found almost everywhere. Sea spray containing marine microorganisms, including cyanobacteria, can be swept high into the atmosphere where they become aeroplankton, and can travel the globe before falling back to earth.
• Unicellular: (a) Synechocystis and (b) Synechococcus elongatus • Non-heterocytous: (c) Arthrospira maxima,• False- or non-branching heterocytous: (f) Nostoc• True-branching heterocytous: (h) Stigonema
Outer and plasma membranes are in blue, thylakoid membranes in gold, glycogen granules in cyan, carboxysomes (C) in green, and a large dense polyphosphate granule (G) in pink
Environmental impact of cyanobacteria and other photosynthetic microorganisms in aquatic systems. Different classes of photosynthetic microorganisms are found in aquatic and marine environments where they form the base of healthy food webs and participate in symbioses with other organisms. However, shifting environmental conditions can result in community dysbiosis, where the growth of opportunistic species can lead to harmful blooms and toxin production with negative consequences to human health, livestock and fish stocks. Positive interactions are indicated by arrows; negative interactions are indicated by closed circles on the ecological model.
Diagnostic Drawing: Cyanobacteria associated with tufa: Microcoleus vaginatus
(1) Cyanobacteria enter the leaf tissue through the stomata and colonize the intercellular space, forming a cyanobacterial loop. (2) On the root surface, cyanobacteria exhibit two types of colonization pattern; in the root hair, filaments of Anabaena and Nostoc species form loose colonies, and in the restricted zone on the root surface, specific Nostoc species form cyanobacterial colonies. (3) Co-inoculation with 2,4-D and Nostoc spp. increases para-nodule formation and nitrogen fixation. A large number of Nostoc spp. isolates colonize the root endosphere and form para-nodules.
Live cyanobionts (cyanobacterial symbionts) belonging to Ornithocercus dinoflagellate host consortium (a) O. magnificus with numerous cyanobionts present in the upper and lower girdle lists (black arrowheads) of the cingulum termed the symbiotic chamber. (b) O. steinii with numerous cyanobionts inhabiting the symbiotic chamber. (c) Enlargement of the area in (b) showing two cyanobionts that are being divided by binary transverse fission (white arrows).
Light microscope view of cyanobacteria from a microbial mat
Types of cell death according to the Nomenclature Committee on Cell Death (upper panel; and proposed for cyanobacteria (lower panel). Cells exposed to extreme injury die in an uncontrollable manner, reflecting the loss of structural integrity. This type of cell death is called "accidental cell death" (ACD). “Regulated cell death (RCD)” is encoded by a genetic pathway that can be modulated by genetic or pharmacologic interventions. Programmed cell death (PCD) is a type of RCD that occurs as a developmental program, and has not been addressed in cyanobacteria yet. RN, regulated necrosis.
Synechococcus uses a gliding technique to move at 25 μm/s. Scale bar is about 10 µm.
Based on data: nodes (1–10) and stars representing common ancestors from Sánchez-Baracaldo et al., 2015, timing of the Great Oxidation Event (GOE), the Lomagundi-Jatuli Excursion, and Gunflint formation. Green lines represent freshwater lineages and blue lines represent marine lineages are based on Bayesian inference of character evolution (stochastic character mapping analyses).
Tree of Life in Generelle Morphologie der Organismen (1866). Note the location of the genus Nostoc with algae and not with bacteria (kingdom "Monera")
Cyanobacteria cultured in specific media: Cyanobacteria can be helpful in agriculture as they have the ability to fix atmospheric nitrogen in soil.
Spirulina tablets
Stromatolites left behind by cyanobacteria are the oldest known fossils of life on Earth. This fossil is one billion years old.
Oncolitic limestone formed from successive layers of calcium carbonate precipitated by cyanobacteria
Oncolites from the Late Devonian Alamo bolide impact in Nevada
{{center|Cyanobacterial remains of an annulated tubular microfossil Oscillatoriopsis longa{{hsp}}<ref>{{cite journal |doi=10.1111/pala.12374 |title=First record of Cyanobacteria in Cambrian Orsten deposits of Sweden |year=2018 |last1=Castellani |first1=Christopher |last2=Maas |first2=Andreas |last3=Eriksson |first3=Mats E. |last4=Haug |first4=Joachim T. |last5=Haug |first5=Carolin |last6=Waloszek |first6=Dieter |journal=Palaeontology |volume=61 |issue=6 |pages=855–880 |s2cid=134049042}}</ref>
Cyanobacteria activity turns Coatepeque Caldera lake a turquoise color
Cyanobacterial bloom near Fiji
Cyanobacteria in Lake Köyliö.

Thick-walled heterocysts – which contain the enzyme nitrogenase vital for nitrogen fixation in an anaerobic environment due to its sensitivity to oxygen.

Structure of the FeMo cofactor showing the sites of binding to nitrogenase. The amino acids cysteine (Cys) and histidine (His) are indicated.

FeMoco

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Structure of the FeMo cofactor showing the sites of binding to nitrogenase. The amino acids cysteine (Cys) and histidine (His) are indicated.

FeMoco (FeMo cofactor) is the primary cofactor of nitrogenase.

Daniel Rutherford, discoverer of nitrogen

Nitrogen

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Chemical element with the symbol N and atomic number 7.

Chemical element with the symbol N and atomic number 7.

Daniel Rutherford, discoverer of nitrogen
The shapes of the five orbitals occupied in nitrogen. The two colours show the phase or sign of the wave function in each region. From left to right: 1s, 2s (cutaway to show internal structure), 2px, 2py, 2pz.
Table of nuclides (Segrè chart) from carbon to fluorine (including nitrogen). Orange indicates proton emission (nuclides outside the proton drip line); pink for positron emission (inverse beta decay); black for stable nuclides; blue for electron emission (beta decay); and violet for neutron emission (nuclides outside the neutron drip line). Proton number increases going up the vertical axis and neutron number going to the right on the horizontal axis.
Molecular orbital diagram of dinitrogen molecule, N2. There are five bonding orbitals and two antibonding orbitals (marked with an asterisk; orbitals involving the inner 1s electrons not shown), giving a total bond order of three.
Solid nitrogen on the plains of Sputnik Planitia on Pluto next to water ice mountains
Structure of [Ru(NH3)5(N2)]2+ (pentaamine(dinitrogen)ruthenium(II)), the first dinitrogen complex to be discovered
Mesomeric structures of borazine, (–BH–NH–)3
Standard reduction potentials for nitrogen-containing species. Top diagram shows potentials at pH 0; bottom diagram shows potentials at pH 14.
Nitrogen trichloride
Nitrogen dioxide at −196 °C, 0 °C, 23 °C, 35 °C, and 50 °C. converts to colourless dinitrogen tetroxide at low temperatures, and reverts to at higher temperatures.
Fuming nitric acid contaminated with yellow nitrogen dioxide
Schematic representation of the flow of nitrogen compounds through a land environment
A container vehicle carrying liquid nitrogen.

These complexes, in which a nitrogen molecule donates at least one lone pair of electrons to a central metal cation, illustrate how N2 might bind to the metal(s) in nitrogenase and the catalyst for the Haber process: these processes involving dinitrogen activation are vitally important in biology and in the production of fertilisers.

Keggin structure of the phosphomolybdate anion (P[Mo12O40]3−), an example of a polyoxometalate

Molybdenum

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Chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6.

Chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6.

Keggin structure of the phosphomolybdate anion (P[Mo12O40]3−), an example of a polyoxometalate
Molybdenite on quartz
World production trend
A plate of molybdenum copper alloy
Structure of the FeMoco active site of nitrogenase.
The molybdenum cofactor (pictured) is composed of a molybdenum-free organic complex called molybdopterin, which has bound an oxidized molybdenum(VI) atom through adjacent sulfur (or occasionally selenium) atoms. Except for the ancient nitrogenases, all known Mo-using enzymes use this cofactor.

These nitrogenases contain an iron-molybdenum cofactor FeMoco, which is believed to contain either Mo(III) or Mo(IV).

Bacteria

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Bacteria (singular bacterium, common noun bacteria) are ubiquitous, mostly free-living organisms often consisting of one biological cell.

Bacteria (singular bacterium, common noun bacteria) are ubiquitous, mostly free-living organisms often consisting of one biological cell.

Rod-shaped Bacillus subtilis
Phylogenetic tree of Bacteria, Archaea and Eucarya. The vertical line at bottom represents the last universal common ancestor.
Bacteria display many cell morphologies and arrangements
The range of sizes shown by prokaryotes (Bacteria), relative to those of other organisms and biomolecules.
Structure and contents of a typical Gram-positive bacterial cell (seen by the fact that only one cell membrane is present).
An electron micrograph of Halothiobacillus neapolitanus cells with carboxysomes inside, with arrows highlighting visible carboxysomes. Scale bars indicate 100 nm.
Helicobacter pylori electron micrograph, showing multiple flagella on the cell surface
Bacillus anthracis (stained purple) growing in cerebrospinal fluid
Many bacteria reproduce through binary fission, which is compared to mitosis and meiosis in this image.
A culture of ''Salmonella
A colony of Escherichia coli
Helium ion microscopy image showing T4 phage infecting E. coli. Some of the attached phage have contracted tails indicating that they have injected their DNA into the host. The bacterial cells are ~ 0.5 µm wide.
Transmission electron micrograph of Desulfovibrio vulgaris showing a single flagellum at one end of the cell. Scale bar is 0.5 micrometers long.
The different arrangements of bacterial flagella: A-Monotrichous; B-Lophotrichous; C-Amphitrichous; D-Peritrichous
Streptococcus mutans visualised with a Gram stain.
Phylogenetic tree showing the diversity of bacteria, compared to other organisms. Here bacteria are represented by three main supergroups: the CPR ultramicrobacterias, Terrabacteria and Gracilicutes according to recent genomic analyzes (2019).
Overview of bacterial infections and main species involved.
Colour-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells
In bacterial vaginosis, beneficial bacteria in the vagina (top) are displaced by pathogens (bottom). Gram stain.
Antonie van Leeuwenhoek, the first microbiologist and the first person to observe bacteria using a microscope.

One example is that some bacteria called diazotrophs have the ability to fix nitrogen gas using the enzyme nitrogenase.

Nif gene

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The nif genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms.

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 (N2) to other nitrogen forms such as ammonia which the organism can use for various purposes.

Cross section though a soybean (Glycine max 'Essex') root nodule: The rhizobacteria, Bradyrhizobium japonicum, colonizes the roots and establishes a nitrogen-fixing symbiosis. This high-magnification image shows part of a cell with single bacteroids within their host plant. In this image, endoplasmic reticulum, dictysome, and cell wall can be seen.

Rhizobacteria

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Rhizobacteria are root-associated bacteria that can have a detrimental (parasitic varieties), neutral or beneficial effect on plant growth.

Rhizobacteria are root-associated bacteria that can have a detrimental (parasitic varieties), neutral or beneficial effect on plant growth.

Cross section though a soybean (Glycine max 'Essex') root nodule: The rhizobacteria, Bradyrhizobium japonicum, colonizes the roots and establishes a nitrogen-fixing symbiosis. This high-magnification image shows part of a cell with single bacteroids within their host plant. In this image, endoplasmic reticulum, dictysome, and cell wall can be seen.

Nitrogenase is an enzyme involved in nitrogen fixation and requires anaerobic conditions.

Azotobacter sp. cells, stained with Heidenhain's iron hematoxylin, ×1000. Vanadium Nitrogenases are found in members of the bacteria genus Azotobacter as well as the species R. palustris and A. variabilis

Vanadium nitrogenase

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Azotobacter sp. cells, stained with Heidenhain's iron hematoxylin, ×1000. Vanadium Nitrogenases are found in members of the bacteria genus Azotobacter as well as the species R. palustris and A. variabilis

Vanadium nitrogenase is a key enzyme for nitrogen fixation found in nitrogen-fixing bacteria, and is used as an alternative to molybdenum nitrogenase when molybdenum is unavailable.