... enzyme Name nitrogenase EC number 1.18.6.1 CAS number 9013 04 1 IUBMB EC number 1 18 6 1 GO code ... Nitrogenase.png thumb Nitrogenase Whilst the equilibrium formation of ammonia from molecular hydrogen ... are supplied to nitrogenase when it associates with the reduced, nucleotide bound homodimeric Fe ... molecule of N sub 2 sub to ammonia. Nitrogenase ultimately bonds each atom of nitrogen to three hydrogen ... . The nitrogenase reaction additionally produces molecular hydrogen as a side product. The exact mechanism of catalysis is unknown due to the difficulty in obtaining crystal s of nitrogen bound to nitrogenase ... at least three electron transfers to perform catalysis . Nitrogenase is able to reduce acetylene, but is inhibited .... Substrate interactions with nitrogenase Fe versus Mo. Biochemistry . 43 6 1401 9. ref All nitrogenases ..., M. Postgate, J. R., 1986, The alternative nitrogenase of Azotobacter chroococcum is a vanadium .... This requires mechanisms for nitrogen fixers to protect nitrogenase from oxygen in vivo . Despite ... is the nitrogenase of Streptomyces thermoautotrophicus , which is unaffected by the presence ... to employ an oxygen labile nitrogenase under aerobic conditions has been attributed to a high metabolic ... , as well as during additional nutrient limitations. ref Oelze J. 2000. Respiratory protection of nitrogenase ... Reactions In addition to performing the reaction N N 2 NH sub 3 sub , nitrogenase is also capable of catalyzing ..., Robert H. title Interactions among substrates and inhibitors of nitrogenase journal J Bacteriol ... Simulation of Nitrogenase Reactions and the Mechanism of Biological Nitrogen Fixation journal ... dioxide as new substrates, and carbon disulfide as a new inhibitor, of nitrogenase journal Biochemistry ... E. Rasche and Lance C. Seefeldt title Reduction of Thiocyanate, Cyanate, and Carbon Disulfide by Nitrogenase ... author Joseph H. Guth, Robert H. Burris title Inhibition of nitrogenase catalyzed ammonia formation ... ref name Seefeldt1 of nitrogenase. Vanadium nitrogenase s have also been shown to catalzye the conversion ... more details
author Rehder D. title Vanadium Nitrogenase journal Journal of Inorganic Biochemistry year 2000 volume ... 2004 volume 22 pages 55 61 doi 10.1038 nbt923 pmid 14704707 ref Vanadium nitrogenase is a key enzyme ... to molybdenum nitrogenase when molybdenum is unavailable. ref name rehder An important component of the nitrogen cycle , vanadium nitrogenase converts nitrogen gas to ammonia, thereby making otherwise inaccessible nitrogen available to plants. Unlike molybdenum nitrogenase, vanadium nitrogenase can ... www.rsc.org chemistryworld News 2010 August 05081001.asp accessdate 2010 08 05 title Nitrogenase Found ... 2004 Most of the functions of vanadium nitrogenase match those of the more common molybdenum nitrogenase .... ref name eady cite journal author Eady R. R. title The Vanadium Nitrogenase of Azotobacter journal ... molybdenum nitrogenase, dihydrogen functions as a competitive inhibition competitive inhibitor and carbon ... as chemical models of the active site of nitrogenase journal Coordination Chemistry Reviews year 2005 volume 249 issue 21 22 pages 2144 2155 doi 10.1016 j.ccr.2005.04.007 ref Vanadium nitrogenase has an sub 2 sub sub 2 sub sub 2 sub protein subunit subunit structure while molybdenum nitrogenase has an sub 2 sub sub 2 sub structure. Though the structural genes encoding vanadium nitrogenase ... type of redox centers. At room temperature, vanadium nitrogenase is less efficient at fixing nitrogen ... activity is 10 times higher than that of molybdenum nitrogenase. ref cite journal author Miller R. W ... favours N2 reduction by vanadium nitrogenase pmc 1135427 journal Biochemistry Journal year 1988 volume 256 issue 2 pages 429 32 pmid 3223922 ref Like molybdenum nitrogenase, vanadium nitrogenase is easily ... fixation catalyzed by vanadium nitrogenase can be summarized as follows ref name rehder N sub ... of vanadium nitrogenase to convert carbon monoxide into trace amounts of propane , ethylene , and ethane ... Vanadium Nitrogenase Reduces CO journal Science year 2010 volume 329 doi 10.1126 science.1191455 ... more details
. nifK encodes for B subunit of Component 1 of nitrogenase. nifD encodes for alpha subunit of component 1 of nitrogenase. nifH encodes for component 2 of nitrogenase. nifEN and nifBQ operons This comprises ... protein. Mo Fe co catalytic site for nitrogenase. nifQ is not absolutely essential. nifJ operon The nifJ ... transfer to nitrogenase. nifUSVM operon The nifS, nifV and nifM genes encode for a protein that is required ... of nitrogenase. Regulation Oxygen The action site of O2 is the nifL protein which is basically ... in the environment inhibits the transcription of nitrogenase and all the other nif genes. NH4 acts as a co ..., NifU. EhNifS and EhNifU were found to be necessary and sufficient for Fe S clusters of non nitrogenase ... 242 ref ref Janet Deistung and Roger N.F.Thorneley,Electron Transfer to nitrogenase,Biochem J. 1986 ... more details
italic title Expert subject Microbiology date November 2008 Taxobox color lightgrey name Azotobacter regnum Bacterium Bacteria phylum Proteobacteria classis Gamma Proteobacteria ordo Pseudomonadales familia Pseudomonadaceae genus Azotobacter species A. vinelandii binomial Azotobacter vinelandii binomial authority Jacob Goodale Lipman Lipman ref cite book title Review of American Chemical Research volume 10 year 1904 editor William A. Noyes page http books.google.com books?id LAoSAAAAIAAJ&pg PA75 v onepage&q&f false 75 ref Azotobacter vinelandii is diazotroph that can fix nitrogen while grown aerobic organism aerobically . It is a genomics genetically tractable system that is used to study nitrogen fixation . These bacteria are easily cultured and grown. It is a free living N sub 2 sub fixer which is known to produce many phytohormone s and vitamin s in the soil. The nitrogenase enzyme holoenzyme of Azotobacter vinelandii has been characterised via x ray crystallography in both Adenosine diphosphate ADP tetrafluoroaluminate bound ref Schindelin, H., Kisker, C., Schlessman, J.L., Howard, J.B., Rees, D.C. 1997 Structure of ADP x AIF4 stabilized nitrogenase complex and its implications for signal transduction. Nature 387 370 376 ref and Mg Adenosine triphosphate ATP bound ref Chiu, H., Peters, J.W., Lanzilotta, W.N., Ryle, M.J., Seefeldt, L.C., Howard, J.B., Rees, D.C. 2001 MgATP Bound and nucleotide free structures of a nitrogenase protein complex between the Leu 127 Delta Fe protein and the MoFe protein. Biochemistry 40 641 650 ref states. The enzyme possesses molybdenum iron sulfido cluster Cofactor biochemistry cofactors FeMoCo as active site s, each bearing 2 pseudo cubic iron sulfido structures. References reflist External links http www.azotobacter.org Azotobacter vinelandii Genome Project http www.micron.ac.uk organisms Avi.html Current research on Azotobacter vinelandii at the Norwich Research Park Category Pseudomonadales Proteobacteria stub es Azotobacter vin ... more details
. It also has the unique characteristic of encoding for a vanadium nitrogenase vanadium containing nitrogenase , which produces as a byproduct of nitrogen fixation three times more hydrogen than the nitrogenase of other bacteria molybennum containing nitrogenase . The potential to manipulate R. palustris ... more details
region. nifH, nifK and nifD encode the nitrogenase s subunits, while nifE, nifN, nifU, nifS, nifV ... into the nitrogenase s subunits. nifF and nifJ encode proteins related to electron transfer taking ... a reversible ADP ribosylation of a specific arginine residue in the nitrogenase complex. The ribosylation ... flow and by so, inactivates nitrogenase s activity. The enzymes catalyzing the ribosylation are called ... more details
others . It was in R. rubrum that, for the first time, post translational regulation of nitrogenase was demonstrated. Nitrogenase is modified by an ADP ribosylation in the arginine residue 101 Arg101 ... modification of the iron protein of nitrogenase from Rhodospirillum rubrum by adenosine diphosphoribosylation ... or ammonia and darkness. ref cite journal author Neilson AH, Nordlund S title Regulation of nitrogenase ... more details
DISPLAYTITLE Rhodobium bacterium Taxobox color lightgrey name Rhodobium regnum Bacterium Bacteria phylum Proteobacteria classis Alpha Proteobacteria ordo Rhizobiales familia Rhodobiaceae genus Rhodobium subdivision ranks Species subdivision R. orientis br R. marina Rhodobium is a genus of purple bacteria purple non sulfur bacteria that reproduces by budding . The cells are rod shaped and reproduce by budding , as in many other members of the Rhizobiales . RNA trees separate it from the others, however, and it is given its own family. R. orientis , the type species, was isolated from seawater in 1995. It is capable of photosynthetic hydrogen production via the nitrogenase enzyme. References Hiraishi A, Urata K, Satoh T. 1995 . A new genus of marine budding phototrophic bacteria, Rhodobium gen. nov., which includes Rhodobium orientis sp. nov. and Rhodobium marinum comb. nov. International Journal of Systematic and Evolutionary Microbiology 45 226 234. DEFAULTSORT Rhodobium Bacterium Category Rhizobiales Proteobacteria stub ... more details
Unreferenced date August 2007 Heterocysts are specialized nitrogen fixation nitrogen fixing cells formed by some filamentous cyanobacteria , such as Nostoc punctiforme , Cylindrospermum stagnale and Anabaena Anabaena sphaerica , during nitrogen starvation. They fix nitrogen from dinitrogen N sub 2 sub in the air using the enzyme nitrogenase , in order to provide the cells in the filament with nitrogen for biosynthesis. 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 expression . For example, heterocysts produce three additional cell wall s, including one of glycolipid that forms a hydrophobic barrier to oxygen produce nitrogenase and other proteins involved in nitrogen fixation degrade photosystem II , which produces oxygen up regulate glycolysis glycolytic enzymes produce proteins that scavenge any remaining oxygen contain polar plugs composed of cyanophycin which slows down cell to cell diffusion Cyanobacteria usually obtain a fixed carbon carbohydrate by photosynthesis . The lack of photosystem II prevents heterocysts from photosynthesizing, so the vegetative cells provide them with carbohydrate s, which is thought to be sucrose . The fixed carbon and nitrogen sources are exchanged through channels between the cells in the filament. Heterocysts maintain photosystem I, allowing them to generate Adenosine triphosphate ATP by light reactions cyclic photophosphorylation . Single heterocysts develop about every 9 15 cells, producing a one dimensional pattern along the filament. The interval between heterocysts remains approximately constant even though the cells in the filament are dividing. The bacterial filament can be seen as a multicellular organism with two distinct yet interdependent cell types. Such behavior is highly unusual in prokaryote s and may have been the first example of multicellular patterning in evolution . Once a heteroc ... more details
enzyme Name protochlorophyllide reductase EC number 1.3.1.33 CAS number 68518 04 7 IUBMB EC number 1 3 1 33 GO code 0016630 image width caption In enzymology , a protochlorophyllide reductase EC number 1.3.1.33 is an enzyme that catalysis catalyzes the chemical reaction chlorophyllide a NADP sup sup math rightleftharpoons math protochlorophyllide NADPH H sup sup Thus, the two substrate biochemistry substrates of this enzyme are chlorophyllide a and nicotinamide adenine dinucleotide phosphate NADP sup sup , whereas its 3 product chemistry products are protochlorophyllide , nicotinamide adenine dinucleotide phosphate NADPH , and hydrogen ion H sup sup . This enzyme belongs to the family of oxidoreductase s, specifically those acting on the CH CH group of donor with NAD or NADP as acceptor. The systematic name of this enzyme class is chlorophyllide a NADP 7,8 oxidoreductase . Other names in common use include NADPH2 protochlorophyllide oxidoreductase , NADPH protochlorophyllide oxidoreductase , NADPH protochlorophyllide reductase , protochlorophyllide oxidoreductase , and protochlorophyllide photooxidoreductase . This enzyme participates in porphyrin and chlorophyll metabolism . There are two structurally unrelated proteins with this activity the light dependent and the dark operative. The light dependent reductase needs light to operate. The dark operative version is a completely different protein, consisting of three subunits that exhibit significant sequence similarity to the three subunits of nitrogenase ref Yuichi FujitaDagger and Carl E. Bauer 2000 . Reconstitution of Light independent Protochlorophyllide Reductase from Purified Bchl and BchN BchB Subunits. J. Biol. Chem., Vol. 275, Issue 31, 23583 23588. http www.jbc.org cgi content abstract 275 31 23583 ref . This enzyme might be evolutionary older but being similar to nitrogenase is highly sensitive to free oxygen and does not work if its concentration exceeds about 3 ref S.Yamazaki, J.Nomata, Y.Fujita 2006 Di ... more details
require oxygen to grow, yet their nitrogenase is still debilitated if exposed to oxygen. Azotobacter ..., having only a single photosystem which cannot split water. Nitrogenase is expressed under nitrogen ... the nitrogenase. ref name Postgate98 Frankia s much less is known about these actinorhizal nitrogen ... more details
chembox verifiedrevid 354478498 ImageFile Homocitric acid.png ImageSize 200px IUPACName 2 hydroxybutane 1,2,4 tricarboxylic acid OtherNames Homocitric acid br Homocitrate Section1 Chembox Identifiers CASNo 3562 74 1 PubChem 28371 ChemSpiderID 26392 SMILES O C O CC O C O O CCC O O InChI 1 C7H10O7 c8 4 9 1 2 7 14,6 12 13 3 5 10 11 h14H,1 3H2, H,8,9 H,10,11 H,12,13 InChIKey XKJVEVRQMLKSMO UHFFFAOYAL StdInChI 1S C7H10O7 c8 4 9 1 2 7 14,6 12 13 3 5 10 11 h14H,1 3H2, H,8,9 H,10,11 H,12,13 StdInChIKey XKJVEVRQMLKSMO UHFFFAOYSA N Section2 Chembox Properties Formula C sub 7 sub H sub 10 sub O sub 7 sub MolarMass 206.15 g mol Appearance colorless solid Density MeltingPtC BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Homocitric acid is an organic compound with the formula HOC CO sub 2 sub H CH sub 2 sub CO sub 2 sub H C sub 2 sub H sub 4 sub CO sub 2 sub H . This tri carboxylic acid occurs naturally as a component of the iron molybdenum cofactor of certain nitrogenase proteins. ref Douglas C. Rees Great Metalloclusters in Enzymology Annual Reviews of Biochemistry 2002, volume 71, pp. 221 46. DOI 10.1146 annurev.biochem.71.110601.135406 ref Biochemists often refer to this cofactor as homocitrate, which is the conjugate bases that predominate in neutral aqueous solutions of this species. The molecule is related to citric acid by the addition of one methylene group, which is implied with the term homo. Unlike citric acid, homocitric acid is Chirality chemistry chiral . The acid exists in equilibrium with the lactone . Image Homocitrate2.png thumb 340px left br style clear left References references Category Hydroxy acids Category Chelating agents Category Tricarboxylic acids biochem stub fa ... more details
File Hodgson.JPG thumb Keith O. Hodgson. Keith O. Hodgson born 1947 ref http www.stanford.edu dept chemistry faculty hodgson Keith O. Hodgson , Stanford University faculty page, accessed 29 10 2010 ref is a Professor of Chemistry at Stanford university and the Stanford Synchrotron Radiation Lightsource . He received his B.S. in 1969 from the University of Virginia and his Ph.D. in 1972 from University of California at Berkeley. His principal research interests include inorganic, bioinorganic, structural and biophysical chemistry. His research group focuses on questions relating to how structure at different organizational levels relates to function. His research is done using a number of different x ray spectroscopic and scattering techniques such as x ray absorption spectroscopy XAS . One of his main area of focus is the active site of the enzyme nitrogenase, which is responsible for conversion of atmospheric dinitrogen to ammonia. Using XAS studies at the S, Fe and Mo edge, his group has worked to understand the electronic structure as a function of redox in this cluster. Other projects include the study of iron in dioxygen activation and oxidation and the role of copper in electron transport and in dioxygen activation. Over his career he has earned the following awards NATO Postdoctoral Fellow, E.T.H. Zurich 1972 73, Alfred P. Sloan Foundation Fellow, 1976 78 Sidhu Award for Contributions to X ray Diffraction, 1978 World Bank Lecturer, 1984, and the Ernest Orlando Lawrence Award in 2002. ref http www.sc.doe.gov lawrence html Laureates 2000s keitho.htm The Ernest Orlando Lawrence Award Keith O. Hodgson 2002 , US Department of Energy Office of Science, accessed 29 10 2010 ref References references External links http www.stanford.edu dept chemistry faculty hodgson Keith O. Hodgson , Stanford University faculty page Persondata Metadata see Wikipedia Persondata . NAME Hodgson, Keith ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1947 PLACE OF BIRTH DATE OF DEATH P ... more details
ferredoxins is implicated in the nitrogenase . Some 4Fe 4S clusters bind substrates and are thus ... complex polymetallic systems are common. Examples include both the 8Fe and the 7Fe clusters in nitrogenase ... system is responsible for the clusters in the enzyme nitrogenase. The suf and isc systems are more ... clusters to nitrogenase journal Curr. Opin. Chem. Biol. year 2002 volume 6 pages 259 273 pmid ... more details
of nitrogen and, is thought to protect the nitrogenase system from oxygen. ref cite journal author ... fixation ferredoxin , hydrogenase and an important enzyme nitrogenase . The process of nitrogen ... Protection nitrogenase complex in Azotobacter vinelandii url http www.inbi.ras.ru ubkh 45 ... a special protein shethna, which protects nitrogenase and is involved in protecting the cells ... author Maier R. J., Moshiri F. title Role of the Azotobacter vinelandii Nitrogenase Protective ... Journal year 2006 volume 397 issue 2 pages 261 270 ref Nitrogenase Main NitrogenaseNitrogenase ... of nitrogenase. The basic one is molybdenum iron nitrogenase. ref cite journal author Howard J. B ... ref An alternative type contains vanadium nitrogenase vanadium it is independent of molybdenum ions ... R. R., Richardson T. H., Miller R. W., Hawkins M., Postgate J. R. title The alternative nitrogenase ... 322 pages 388 390 issue 6077 ref and is more active than the Mo Fe nitrogenase at low temperatures ... higher than that of Mo Fe nitrogenase. ref cite journal author Miller R. W., Eady R. R. title Molybdenum ... nitrogenase. pmc 1135427 journal Biochemistry Journal year 1988 volume 256 issue 2 pages 429 432 pmid 3223922 ref An important role in maturation of Mo Fe nitrogenase plays the so called P ... on nitrogenase MoFe protein journal Proceedings of the National Academy of Sciences of the United States ... pages 10424 10429 ref Synthesis of nitrogenase is controlled by the nif genes. ref cite journal doi ... for rapid expression of nitrogenase activity in Azotobacter vinelandii pmid 15845763 journal Proceedings ... more details
sensitive nitrogenase an enzyme responsible for the fixation of atmospheric nitrogen. Leghemoglobin ... an oxygen concentration that is low enough to allow nitrogenase to function but high enough ... more details
Taxobox name Trichodesmium regnum Bacteria phylum Cyanobacteria ordo Oscillatoriales genus Trichodesmium subdivision ranks Species subdivision Trichodesmium contortum T. contortum br Trichodesmium erythraeum T. erythraeum br Trichodesmium hildebrandtii T. hildebrandtii br Trichodesmium tenue T. tenue br Trichodesmium thiebautii T. thiebautii sea sawdust directs here, hence bold for that Trichodesmium , also called sea sawdust , is a genus of Filamentation filamentous cyanobacteria . They are found in nutrient poor tropical and subtropical ocean waters particularly around Australia and the red sea , where they were first described by Captain Cook . Trichodesmium nitrogen fixation fixes atmospheric nitrogen into ammonium, usable also for other organisms. While far from the only nitrogen fixing bacterium bacteria , they are among the most important of the marine varieties, and are being extensively studied for their role in nutrient cycling in the ocean. Unlike other nitrogen fixing bacteria, Trichodesmium does not have heterocyst s, nor any other specialised cells for this task. Furthermore, nitrogen fixation peaks at midday, i.e. occurs during the same time as photosynthesis. Inhibitor studies even revealed that photosystem II activity is essential for nitrogen fixation in this organism. All this may seem contradictory at first glance, because the enzyme responsible for nitrogen fixation, nitrogenase , is irreversibly inhibited by oxygen. However, Trichodesmium utilises photosynthesis for nitrogen fixation by carrying out the Mehler reaction , during which the oxygen produced by PSII is reduced again after PSI. This regulation of photosynthesis for nitrogen fixation involves rapidly reversible coupling of their light harvesting antenna, the phycobilisome s, with PSI and PSII. Trichodesmium forms blooms and provides substrate for many small oceanic organisms bacteria , diatoms , dinoflagellates , protozoa , and copepods . References Kana TM 1993 Rapid oxygen cycling i ... more details
Chembox verifiedrevid 444017528 ImageFile Molybdenum cofactor.svg ImageSize 200px IUPACName OtherNames Moco Section1 Chembox Identifiers CASNo Ref cascite correct ?? CASNo 872689 63 9 PubChem 25202532 DrugBank Ref drugbankcite correct drugbank DrugBank DB02137 SMILES S C1 C S C N2 C OC1COP O O O NC3 C2C N C N N3 O.O Mo 2 O Section2 Chembox Properties C 10 H 12 Mo 1 N 5 O 8 P 1 S 2 Appearance Density MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Image MoPtSyn.png thumb 300px right Some biosynthetic steps leading to molybdenum pterin, a molydopterin. Molybdenum cofactor is a Cofactor biochemistry cofactor required for the activity of enzyme s such as sulfite oxidase , xanthine oxidoreductase , and aldehyde oxidase . ref name pmid16261263 cite journal author Schwarz G title Molybdenum cofactor biosynthesis and deficiency journal Cell. Mol. Life Sci. volume 62 issue 23 pages 2792 810 year 2005 month December pmid 16261263 doi 10.1007 s00018 005 5269 y url issn ref ref name pmid18411266 cite journal author Smolinsky B, Eichler SA, Buchmeier S, Meier JC, Schwarz G title Splice specific functions of gephyrin in molybdenum cofactor biosynthesis journal J. Biol. Chem. volume 283 issue 25 pages 17370 9 year 2008 month June pmid 18411266 doi 10.1074 jbc.M800985200 url issn ref It is a coordination complex formed between molybdopterin which, despite the name, does not contain molybdenum and an oxide of molybdenum . Molybdopterins, in turn, are synthesized from guanosine triphosphate see synthetic route at right . Molybdenum cofactor functions directly in ethylbenzene dehydrogenase , glyceraldehyde 3 phosphate ferredoxin oxidoreductase , and respiratory arsenate reductase In animals and plants these enzymes use molybdenum bound at the active site in a tricyclic molybdenum cofactor . All molybdenum using enzymes so far identified in nature use this cofactor, save for the phylogenetically ancient molybdenum nitrogenase s, which fix nitrog ... more details
of three subunits that exhibit significant sequence similarity to the three subunits of nitrogenase ... abstract 275 31 23583 ref This enzyme might be evolutionary older but being similar to nitrogenase ... more details
atmospheric nitrogen is converted to ammonia by an enzyme called nitrogenase . ref name postgate ... formation of one molecule of H sub 2 sub . In free living diazotrophs, the nitrogenase generated .... Enzymes responsible for nitrogenase action are very susceptible to destruction by oxygen. Many bacteria ... Carver Nif gene Nitrification Nitrogen cycle Nitrogen deficiency Nitrogenase Push pull technology ... more details
Image NodSm IV Ac,C16 2,S .svg right thumb 300px The structure of nod factor from Sinorhizobium meliloti . Nodulation Nod factors are signaling molecule s produced by bacteria known as rhizobia during the initiation of root nodule nodules on the root of legume s. A symbiosis is formed when legumes take up the bacteria. The rhizobia produce nitrogen for the plant, and the legumes produce leghemoglobin to carry away any oxygen that would inhibit nitrogenase activity. Nod factors structurally are lipochitooligosaccharides LCOs that consist of an acylation acylated chitin oligomeric backbone with various functional group substitutions at the terminal or non terminal residues. The number of N acetylglucosamine molecules vary among Nod factors however, generally the length of a chitin backbone is from 3 to 5. The exact chemical structure of the Nod factor that is recognised by the plant varies between bacterial species and is the basis for host symbiont specificity. Nod factors are recognized by a specific class of Receptor biochemistry receptor kinase s that have so called LysM protein domain domain s in their extracellular domains. The two LysM lysin motif receptor kinases NFR1 and NFR5 that appear to make up the Nod factor receptor were first isolated in the model organism model legume Lotus japonicus in 2003. They now have been isolated also from soybean and the model legume Medicago truncatula . NFR5 lacks the classical activation loop in the kinase domain . The NFR5 gene lacks intron s. Nod gene expression is induced by the presence of certain flavonoid s in the soil, which are secreted by the plant to attract the bacteria ref Jos Angelo Silveira Zuanazzi, Pierre Henri Clergeot, Jean Charles Quirion, Henri Philippe Husson, Adam Kondorosi,1 and Pascal Ratet 1998 . Production of Sinorhizobium meliloti nod Gene Activator and Repressor Flavonoids from Medicago sativa Roots Molecular Plant Microbe Interactions 11 784 794 ref . These chemicals induce the formation of Nod ... more details
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