2.02012-05-31 13:57:05 -06002015-09-17 15:41:16 -0600ECMDB02786M2MDB000465NitriteA nitrite compound is either a salt or an ester of nitrous acid. Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, in a reaction with the meat's myoglobin, gives the product a desirable dark red color. Nitrite can be reduced to nitric oxide or ammonia by many species of bacteria. Several mechanisms for nitrite conversion to NO have been described including enzymatic reduction by xanthine oxidoreductase and NO synthase (NOS), as well as nonenzymatic acidic disproportionation. -- WikipediaNitriteNitrite anionNitrite ionNitrogen dioxideNitrogen dioxide ionNitrogen peroxide ionNO2NO2-NO<sub>2</sub>NO<sub>2</sub><sup>-</sup>NO246.005545.992903249nitrous acidnitrous acid14797-65-0[O-]N=OInChI=1S/HNO2/c2-1-3/h(H,2,3)/p-1IOVCWXUNBOPUCH-UHFFFAOYSA-MSolidCytosolExtra-organismPeriplasmlogp0.17pka_strongest_basic-3.5iupacnitrous acidaverage_mass46.0055mono_mass45.992903249smiles[O-]N=OformulaNO2inchiInChI=1S/HNO2/c2-1-3/h(H,2,3)/p-1inchikeyIOVCWXUNBOPUCH-UHFFFAOYSA-Mpolar_surface_area49.66refractivity8.72polarizability2.81rotatable_bond_count0acceptor_count3donor_count1physiological_charge0formal_charge0Nitrogen 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.
PW000755ec00910MetabolicMicrobial metabolism in diverse environmentsec01120ABC transportersec02010Two-component systemec02020nitrate reduction VIIIIn 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.PW002092Metabolicnitrate reduction III (dissimilatory)PWY0-1321nitrate reduction VIII (dissimilatory)PWY0-1352Specdb::CMs158116Specdb::MsMs29534Specdb::MsMs29535Specdb::MsMs29536Specdb::MsMs36092Specdb::MsMs36093Specdb::MsMs36094Specdb::MsMs1218085Specdb::MsMs1218086Specdb::MsMs1218087Specdb::MsMs2326815Specdb::MsMs2326816Specdb::MsMs2326817Specdb::MsMs2611810Specdb::MsMs2611811Specdb::MsMs2611812HMDB02786921C0008816301NITRITENO2NitriteKeseler, 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-D590.21097882Kanehisa, 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-D114.22080510Nakata, Sumio; Eiki, Toshio; Tanaka, Norihiro; Koyama, Tadashi; Tsukui, Hiroto; Watanabe, Shizuo. Production of nitrite ions from trinitrophenyl myosin and from trinitrophenyl subfragment-1. Journal of Biochemistry (Tokyo, Japan) (1986), 99(1), 27-http://hmdb.ca/system/metabolites/msds/000/002/369/original/HMDB02786.pdf?1358463356Nitrite reductase [NAD(P)H] large subunitP08201NIRB_ECOLInirBhttp://ecmdb.ca/proteins/P08201.xmlRespiratory nitrate reductase 1 alpha chainP09152NARG_ECOLInarGhttp://ecmdb.ca/proteins/P09152.xmlNitrite reductase [NAD(P)H] small subunitP0A9I8NIRD_ECOLInirDhttp://ecmdb.ca/proteins/P0A9I8.xmlCytochrome c-552P0ABK9NRFA_ECOLInrfAhttp://ecmdb.ca/proteins/P0ABK9.xmlRespiratory nitrate reductase 2 gamma chainP0AF32NARV_ECOLInarVhttp://ecmdb.ca/proteins/P0AF32.xmlRespiratory nitrate reductase 1 beta chainP11349NARH_ECOLInarHhttp://ecmdb.ca/proteins/P11349.xmlRespiratory nitrate reductase 1 gamma chainP11350NARI_ECOLInarIhttp://ecmdb.ca/proteins/P11350.xmlProbable nitrate reductase molybdenum cofactor assembly chaperone NarWP19317NARW_ECOLInarWhttp://ecmdb.ca/proteins/P19317.xmlRespiratory nitrate reductase 2 beta chainP19318NARY_ECOLInarYhttp://ecmdb.ca/proteins/P19318.xmlRespiratory nitrate reductase 2 alpha chainP19319NARZ_ECOLInarZhttp://ecmdb.ca/proteins/P19319.xmlPeriplasmic nitrate reductaseP33937NAPA_ECOLInapAhttp://ecmdb.ca/proteins/P33937.xmlFerredoxin-type protein napGP0AAL3NAPG_ECOLInapGhttp://ecmdb.ca/proteins/P0AAL3.xmlFerredoxin-type protein napHP33934NAPH_ECOLInapHhttp://ecmdb.ca/proteins/P33934.xmlProtein nrfDP32709NRFD_ECOLInrfDhttp://ecmdb.ca/proteins/P32709.xmlProtein nrfCP0AAK7NRFC_ECOLInrfChttp://ecmdb.ca/proteins/P0AAK7.xmlCytochrome c-type protein nrfBP0ABL1NRFB_ECOLInrfBhttp://ecmdb.ca/proteins/P0ABL1.xmlDiheme cytochrome c napBP0ABL3NAPB_ECOLInapBhttp://ecmdb.ca/proteins/P0ABL3.xmlCytochrome c-type protein napCP0ABL5NAPC_ECOLInapChttp://ecmdb.ca/proteins/P0ABL5.xmlNitrate reductase molybdenum cofactor assembly chaperone NarJP0AF26NARJ_ECOLInarJhttp://ecmdb.ca/proteins/P0AF26.xmlpredicted 2Fe-2S cluster-containing proteinP0ABR7yeaWhttp://ecmdb.ca/proteins/P0ABR7.xmlheme lyase (NrfEFG) for insertion of heme into c552, subunit NrfEP32710nrfEhttp://ecmdb.ca/proteins/P32710.xmlProbable nitrite transporterP0AC26NIRC_ECOLInirChttp://ecmdb.ca/proteins/P0AC26.xmlOuter membrane protein NP77747OMPN_ECOLIompNhttp://ecmdb.ca/proteins/P77747.xmlOuter membrane pore protein EP02932PHOE_ECOLIphoEhttp://ecmdb.ca/proteins/P02932.xmlNitrite extrusion protein 1P10903NARK_ECOLInarKhttp://ecmdb.ca/proteins/P10903.xmlOuter membrane protein FP02931OMPF_ECOLIompFhttp://ecmdb.ca/proteins/P02931.xmlOuter membrane protein CP06996OMPC_ECOLIompChttp://ecmdb.ca/proteins/P06996.xmlNitrite extrusion protein 2P37758NARU_ECOLInarUhttp://ecmdb.ca/proteins/P37758.xml2 Hydrogen ion + Nitrate + Ubiquinol-8 > Water + Nitrite + Ubiquinone-8 +2 Hydrogen ion2 Hydrogen ion + Menaquinol 8 + Nitrate > Water + Menaquinone 8 + Nitrite +2 Hydrogen ionUbiquinol-8 + Nitrate > Ubiquinone-8 + Water + NitriteMenaquinol 8 + Nitrate > Menaquinone 8 + Water + Nitrite5 Hydrogen ion + 3 NADH + Nitrite >2 Water +3 NAD + Ammonium3 Ubiquinol-8 + 2 Hydrogen ion + Nitrite >3 Ubiquinone-8 +2 Water + Ammonium3 Menaquinol 8 + 2 Hydrogen ion + Nitrite >3 Menaquinone 8 +2 Water + AmmoniumAmmonium hydroxide + 3 NAD + Water + Ammonia <> Nitrite +3 NADH +3 Hydrogen ionR00787Ammonium hydroxide + 3 NADP + Water <> Nitrite +3 NADPH +3 Hydrogen ionR00789Nitrite + Acceptor + Water + Acceptor <> Nitrate + Reduced acceptor + Reduced acceptorR007982 Ferricytochrome c + Nitrite + Water <> Nitrate +2 Ferrocytochrome c +2 Hydrogen ionR011064-Nitrocatechol + Oxygen + 3 Hydrogen ion <> Benzene-1,2,4-triol + Nitrite + WaterR05265Ammonia + 2 Water + 6 Ferricytochrome c + Ferricytochrome c <> Nitrite +6 Ferrocytochrome c +6 Hydrogen ion + Ferrocytochrome cR05712Nitrobenzene + Oxygen <> Pyrocatechol + NitriteR07706Nitrite + Water + Cytochromes-C-Oxidized <> Nitrate + Cytochromes-C-ReducedR247-RXNa menaquinol + Nitrate + Hydrogen ion > a menaquinone + Nitrite + Water + Hydrogen ionRXN0-3501Nitrate + a ubiquinol > Nitrite + Water + a ubiquinoneRXN0-6369Nitrate + Hydrogen ion > Nitrite + WaterRXN0-6370NAD(P)H + Nitrite + Hydrogen ion > NAD(P)<sup>+</sup> + Ammonium + WaterRXN0-6377Nitrite + acceptor > Nitrate + reduced acceptorAmmonium hydroxide + 3 NAD(P)(+) + Water > Nitrite +3 NAD(P)HAmmonia + 2 Water + 6 Ferricytochrome c > Nitrite +6 Ferrocytochrome c +7 Hydrogen ionAmmonia + NAD + 3 NADP + 2 Water <> Nitrite + NADH +3 NADPH +5 Hydrogen ionR00787 R00789 Nitrite + Nitrite > NitritePW_R002425Nitrate + cytochrome c nitrite reductase + Nitrate <> Nitrite + cytochrome c nitrite reductase + Water + NitritePW_R002426Nitrite + 3 NADH + 5 Hydrogen ion + Nitrite Ammonia +2 Water +3 NADPW_R002427Nitrite + 6 ferrocytochrome c + 7 Hydrogen ion + Nitrite + 6 Ferrocytochrome c <> Ammonia +6 ferricytochrome c +2 Water +6 Ferricytochrome cPW_R002428Nitrate + 2 Hydrogen ion + a menaquinol > Nitrite + Water + a menaquinonePW_RCT000191Nitrite + Acceptor + Water <> Nitrate + Reduced acceptorAmmonia + NAD + 3 NADP + 2 Water <> Nitrite + NADH +3 NADPH +5 Hydrogen ionNitrite + Acceptor + Water <> Nitrate + Reduced acceptorAmmonia + NAD + 3 NADP + 2 Water <> Nitrite + NADH +3 NADPH +5 Hydrogen ionNitrite + Acceptor + Water <> Nitrate + Reduced acceptorNitrite + Acceptor + Water <> Nitrate + Reduced acceptor