2.0 2012-05-31 13:57:15 -0600 2015-09-17 15:41:16 -0600 ECMDB02878 M2MDB000468 Nitrate Nitrate is a salt of nitric acid. In organic chemistry the esters of nitric acid and various alcohols are called nitrates. The nitrate ion is a polyatomic anion with the empirical formula NO3- and a molecular mass of 62.01 daltons; it consists of one central nitrogen atom surrounded by three identical oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a negative one formal charge. Nitrates should not be confused with nitrites, the salts of nitrous acid. Organic compounds containing the nitro functional group (which has the same formula and structure as the nitrate ion save that one of the O2 atoms is replaced by the R group) are known as nitro compounds. Nitrate ions can be toxic. Econazole Nitrate Econazole Nitric acid Femstat 3 Ganite Gynazole-1 Isordil Isosorbide Dinitrate Isosorbide Dinitric acid Nitrate Nitrate ion Nitric acid Nitric acid ion NO3 NO3- NO<SUB>3</SUB> NO<SUB>3</SUB><SUP>-</SUP> Sorbitrate Sorbitric acid Trioxidonitrate Trioxidonitric acid Trioxonitrate Trioxonitric acid NO3 62.0049 61.987817871 nitric acid nitric acid 14797-55-8 [O-][N+]([O-])=O InChI=1S/NO3/c2-1(3)4/q-1 NHNBFGGVMKEFGY-UHFFFAOYSA-N Solid Cytosol Extra-organism Periplasm logp 0.028 ChemAxon pka_strongest_acidic -1.4 ChemAxon pka_strongest_basic -6.1 ChemAxon iupac nitric acid ChemAxon average_mass 62.0049 ChemAxon mono_mass 61.987817871 ChemAxon smiles [O-][N+]([O-])=O ChemAxon formula NO3 ChemAxon inchi InChI=1S/NO3/c2-1(3)4/q-1 ChemAxon inchikey NHNBFGGVMKEFGY-UHFFFAOYSA-N ChemAxon polar_surface_area 66.05 ChemAxon refractivity 10.47 ChemAxon polarizability 3.55 ChemAxon rotatable_bond_count 0 ChemAxon acceptor_count 3 ChemAxon donor_count 1 ChemAxon physiological_charge -1 ChemAxon formal_charge 0 ChemAxon Nitrogen metabolism The biological process of the nitrogen cycle is a complex interplay among many microorganisms catalyzing different reactions, where nitrogen is found in various oxidation states ranging from +5 in nitrate to -3 in ammonia. The ability of fixing atmospheric nitrogen by the nitrogenase enzyme complex is present in restricted prokaryotes (diazotrophs). The other reduction pathways are assimilatory nitrate reduction and dissimilatory nitrate reduction both for conversion to ammonia, and denitrification. Denitrification is a respiration in which nitrate or nitrite is reduced as a terminal electron acceptor under low oxygen or anoxic conditions, producing gaseous nitrogen compounds (N2, NO and N2O) to the atmosphere. Nitrate can be introduced into the cytoplasm through a nitrate:nitrite antiporter NarK or a nitrate / nitrite transporter NarU. Nitrate is then reduced by a Nitrate Reductase resulting in the release of water, an acceptor and a Nitrite. Nitrite can also be introduced into the cytoplasm through a nitrate:nitrite antiporter NarK Nitrite can be reduced a NADPH dependent nitrite reductase resulting in water and NAD and Ammonia. Nitrite can interact with hydrogen ion, ferrocytochrome c through a cytochrome c-552 ferricytochrome resulting in the release of ferricytochrome c, water and ammonia Another process by which ammonia is produced is by a reversible reaction of hydroxylamine with a reduced acceptor through a hydroxylamine reductase resulting in an acceptor, water and ammonia. Water and carbon dioxide react through a carbonate dehydratase resulting in carbamic acid. This compound reacts spontaneously with hydrogen ion resulting in the release of carbon dioxide and ammonia. Carbon dioxide can interact with water through a carbonic anhydrase resulting in hydrogen carbonate. This compound interacts with cyanate and hydrogen ion through a cyanate hydratase resulting in a carbamic acid. Ammonia can be metabolized by reacting with L-glutamine and ATP driven glutamine synthetase resulting in ADP, phosphate and L-glutamine. The latter compound reacts with oxoglutaric acid and hydrogen ion through a NADPH dependent glutamate synthase resulting in the release of NADP and L-glutamic acid. L-glutamic acid reacts with water through a NADP-specific glutamate dehydrogenase resulting in the release of oxoglutaric acid, NADPH, hydrogen ion and ammonia. PW000755 ec00910 Metabolic Microbial metabolism in diverse environments ec01120 ABC transporters ec02010 Two-component system ec02020 nitrate reduction VIII In the anaerobic respiratory chain formed by NADH dehydrogenase and nitrate reductase the transfer of electrons from NADH to nitrate is coupled to the generation of a proton-motive force (H+/e- = 3) across the cytoplasmic membrane. E. coli K-12 contains two NADH dehydrogenases - energy conserving NDH-I and NDH-II which does not contribute to the proton gradient; both enzymes appear to be involved in anaerobic nitrate respiration. By analogy to the related enzyme from mitochondria, NDH-I is thought to function as a proton pump translocating 4H+ per NADH oxidised (2e-) [H+/e- = 2] however a lower ratio of 3H+/2e- has also been proposed. Nitrate induces the expression of the nuo operon (encoding NDH-I) in a NarL dependent manner. E. coli K-12 also contains two energy conserving (H+/e- = 1) nitrate reductases. Expression of nitrate reductase A (NRA) occurs in response to high levels of nitrate in the environment whereas expression of nitrate reductase Z (NRZ) is not dependent on nitrate levels or anaerobiosis. Quinones are the obligate redox carriers during anaerobic nitrate respiration; the concentration of menaquinone increases in cells grown anaerobically with nitrate while the concentration of ubiquinone decreases (as compared with cells grown aerobically). Nitrate reductase A can use both menaquinol and ubiquinol as electron donors. In anaerobic growth with nitrate the major quinone is demethylmenaquinone (DMK); an E. coli strain containing only demethylmenaquinone is unable to grow with nitrate as terminal reductase. PW002092 Metabolic nitrate reduction III (dissimilatory) PWY0-1321 nitrate reduction VIII (dissimilatory) PWY0-1352 Specdb::MsMs 29210 Specdb::MsMs 29211 Specdb::MsMs 29212 Specdb::MsMs 35768 Specdb::MsMs 35769 Specdb::MsMs 35770 HMDB02878 943 918 C00244 17632 NITRATE NO3 Nitrate Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. 21097882 Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114. 22080510 http://hmdb.ca/system/metabolites/msds/000/002/461/original/HMDB02878.pdf?1358459987 Respiratory nitrate reductase 1 alpha chain P09152 NARG_ECOLI narG http://ecmdb.ca/proteins/P09152.xml Respiratory nitrate reductase 2 gamma chain P0AF32 NARV_ECOLI narV http://ecmdb.ca/proteins/P0AF32.xml Respiratory nitrate reductase 1 beta chain P11349 NARH_ECOLI narH http://ecmdb.ca/proteins/P11349.xml Respiratory nitrate reductase 1 gamma chain P11350 NARI_ECOLI narI http://ecmdb.ca/proteins/P11350.xml Probable nitrate reductase molybdenum cofactor assembly chaperone NarW P19317 NARW_ECOLI narW http://ecmdb.ca/proteins/P19317.xml Respiratory nitrate reductase 2 beta chain P19318 NARY_ECOLI narY http://ecmdb.ca/proteins/P19318.xml Respiratory nitrate reductase 2 alpha chain P19319 NARZ_ECOLI narZ http://ecmdb.ca/proteins/P19319.xml Flavohemoprotein P24232 HMP_ECOLI hmp http://ecmdb.ca/proteins/P24232.xml Periplasmic nitrate reductase P33937 NAPA_ECOLI napA http://ecmdb.ca/proteins/P33937.xml Ferredoxin-type protein napG P0AAL3 NAPG_ECOLI napG http://ecmdb.ca/proteins/P0AAL3.xml Ferredoxin-type protein napH P33934 NAPH_ECOLI napH http://ecmdb.ca/proteins/P33934.xml Diheme cytochrome c napB P0ABL3 NAPB_ECOLI napB http://ecmdb.ca/proteins/P0ABL3.xml Cytochrome c-type protein napC P0ABL5 NAPC_ECOLI napC http://ecmdb.ca/proteins/P0ABL5.xml Nitrate reductase molybdenum cofactor assembly chaperone NarJ P0AF26 NARJ_ECOLI narJ http://ecmdb.ca/proteins/P0AF26.xml Outer membrane protein N P77747 OMPN_ECOLI ompN http://ecmdb.ca/proteins/P77747.xml Outer membrane pore protein E P02932 PHOE_ECOLI phoE http://ecmdb.ca/proteins/P02932.xml Nitrite extrusion protein 1 P10903 NARK_ECOLI narK http://ecmdb.ca/proteins/P10903.xml Outer membrane protein F P02931 OMPF_ECOLI ompF http://ecmdb.ca/proteins/P02931.xml Outer membrane protein C P06996 OMPC_ECOLI ompC http://ecmdb.ca/proteins/P06996.xml Nitrite extrusion protein 2 P37758 NARU_ECOLI narU http://ecmdb.ca/proteins/P37758.xml 2 Hydrogen ion + Nitrate + Ubiquinol-8 > Water + Nitrite + Ubiquinone-8 +2 Hydrogen ion 2 Hydrogen ion + Menaquinol 8 + Nitrate > Water + Menaquinone 8 + Nitrite +2 Hydrogen ion Ubiquinol-8 + Nitrate > Ubiquinone-8 + Water + Nitrite Menaquinol 8 + Nitrate > Menaquinone 8 + Water + Nitrite NADH + 2 Nitric oxide + 2 Oxygen > Hydrogen ion + NAD +2 Nitrate NADPH + 2 Nitric oxide + 2 Oxygen > Hydrogen ion + NADP +2 Nitrate Nitrite + Acceptor + Water + Acceptor <> Nitrate + Reduced acceptor + Reduced acceptor R00798 2 Ferricytochrome c + Nitrite + Water <> Nitrate +2 Ferrocytochrome c +2 Hydrogen ion R01106 Nitrite + Water + Cytochromes-C-Oxidized <> Nitrate + Cytochromes-C-Reduced R247-RXN NAD(P)H + Nitric oxide + Oxygen > NAD(P)⁺ + Nitrate + Hydrogen ion R621-RXN a menaquinol + Nitrate + Hydrogen ion > a menaquinone + Nitrite + Water + Hydrogen ion RXN0-3501 Nitrate + a ubiquinol > Nitrite + Water + a ubiquinone RXN0-6369 Nitrate + Hydrogen ion > Nitrite + Water RXN0-6370 2 Nitric oxide + 2 Oxygen + NAD(P)H >2 Nitrate + NAD(P)(+) Nitrite + acceptor > Nitrate + reduced acceptor Nitric oxide + 2 Oxygen + NADH + NADPH <>2 Nitrate + NAD + NADP + Hydrogen ion R05724 R05725 Nitrate + Nitrate > Nitrate PW_R002424 Nitrate + cytochrome c nitrite reductase + Nitrate <> Nitrite + cytochrome c nitrite reductase + Water + Nitrite PW_R002426 Nitrate + 2 Hydrogen ion + a menaquinol > Nitrite + Water + a menaquinone PW_RCT000191 Nitrite + Acceptor + Water <> Nitrate + Reduced acceptor Nitrite + Acceptor + Water <> Nitrate + Reduced acceptor Nitrite + Acceptor + Water <> Nitrate + Reduced acceptor Nitrite + Acceptor + Water <> Nitrate + Reduced acceptor