2.0 2012-05-31 13:50:50 -0600 2015-09-17 16:24:07 -0600 ECMDB01362 M2MDB000355 Hydrogen (gas) Hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H2. With an atomic weight of 1.00794, hydrogen is the lightest element. Besides the common H1 isotope, hydrogen exists as the stable isotope Deuterium and the unstable, radioactive isotope Tritium. Hydrogen is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass. Hydrogen can form compounds with most elements and is present in water and most organic compounds. It plays a particularly important role in acid-base chemistry, in which many reactions involve the exchange of protons between soluble molecules. Oxidation of hydrogen, in the sense of removing its electron, formally gives H+, containing no electrons and a nucleus which is usually composed of one proton. That is why H+ is often called a proton. This species is central to discussion of acids. Under the Bronsted-Lowry theory, acids are proton donors, while bases are proton acceptors. The transport of protons or hydrogen ions across the membrane(ie the creation of a proton gradient) is critical to the generation of energy (ATP) for all living cells. Dihydrogen Hydrogen Hydrogen cation Hydrogen gas Hydrogen ion Hydrogen molecule Hydronium Proton H2 2.0159 2.015650064 dihydrogen dihydrogen 1333-74-0 [H][H] InChI=1S/H2/h1H UFHFLCQGNIYNRP-UHFFFAOYSA-N Liquid Cytosol Extra-organism Periplasm melting_point -259.2 oC iupac dihydrogen ChemAxon average_mass 2.0159 ChemAxon mono_mass 2.015650064 ChemAxon smiles [H][H] ChemAxon formula H2 ChemAxon inchi InChI=1S/H2/h1H ChemAxon inchikey UFHFLCQGNIYNRP-UHFFFAOYSA-N ChemAxon polar_surface_area 0 ChemAxon refractivity 0 ChemAxon polarizability 0.74 ChemAxon rotatable_bond_count 0 ChemAxon acceptor_count 0 ChemAxon donor_count 0 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Methane metabolism ec00680 Trinitrotoluene degradation ec00633 Microbial metabolism in diverse environments ec01120 2,3-dihydroxybenzoate biosynthesis 2,3-dihydroxybenzoate is synthesized from chorismate via isochorismate and 2,3-dihydroxy-2,3-dihydrobenzoate. Chorismate is a key intermediate and branch point in the biosynthesis of many aromatic compounds. The biosynthesis of 2,3-dihydroxybenzoate from chorismate is catalyzed by three enzymes EntC, EntB, and EntA. EntC catalyzes the conversion of chorismate to isochorismate. The N-terminal isochorismate lyase domain of EntB hydrolyzes the pyruvate group of isochorismate to produce 2,3-dihydro-2,3-dihydroxybenzoate. The conversion of this latter compound to 2,3-dihydroxybenzoate is catalyzed by the EntA dehydrogenase. PW000751 Metabolic Menaquinol biosythesis Menaquinol biosynthesis starts with chorismate being metabolized into isochorismate through a isochorismate synthase. Isochorismate then interacts with 2-oxoglutare and a hydrogen ion through a 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate synthase resulting in the release of a carbon dioxide and a 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate. The latter compound then interacts with (1R,6R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase resulting in the release of a pyruvate and a (1R,6R)-6-hydroxy-2-succinylcyclohexa-2,4-diene-1-carboxylate. This compound is the dehydrated through a o-succinylbenzoate synthase resulting in the release of a water molecule and a 2-succinylbenzoate. This compound then interacts with a coenzyme A and an ATP through a o-succinylbenzoate CoA ligase resulting in the release of a diphosphate, a AMP and a succinylbenzoyl-CoA. The latter compound interacts with a hydrogen ion through a 1,4-dihydroxy-2-naphthoyl-CoA synthase resulting in the release of a water molecule or a 1,4-dihydroxy-2-naphthoyl-CoA. This compound then interacts with water through a 1,4-dihydroxy-2-naphthoyl-CoA thioesterase resulting in the release of a coenzyme A, a hydrogen ion and a 1,4-dihydroxy-2-naphthoate. The 1,4-dihydroxy-2-naphthoate can interact with either farnesylfarnesylgeranyl-PP or octaprenyl diphosphate and a hydrogen ion through a 1,4-dihydroxy-2-naphthoate octaprenyltransferase resulting in a release of a carbon dioxide, a pyrophosphate and a demethylmenaquinol-8. This compound then interacts with SAM through a bifunctional 2-octaprenyl-6-methoxy-1,4-benzoquinone methylase and S-adenosylmethionine:2-DMK methyltransferase resulting in a hydrogen ion, a s-adenosyl-L-homocysteine and a menaquinol. PW001897 Metabolic mixed acid fermentation FERMENTATION-PWY respiration (anaerobic) ANARESP1-PWY Specdb::MsMs 24629 Specdb::MsMs 24630 Specdb::MsMs 24631 Specdb::MsMs 31187 Specdb::MsMs 31188 Specdb::MsMs 31189 HMDB01362 5362549 4515072 C00282 29235 HYDROGEN-MOLECULE Hydrogen 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 Ait-Ichou, I.; Formenti, M.; Pommier, B.; Teichner, S. J. Photocatalytic dehydrogenation of isopropanol on platinum/titania catalysts. Journal of Catalysis (1985), 91(2), 293-307. Alkaline phosphatase P00634 PPB_ECOLI phoA http://ecmdb.ca/proteins/P00634.xml Formate dehydrogenase H P07658 FDHF_ECOLI fdhF http://ecmdb.ca/proteins/P07658.xml Formate hydrogenlyase subunit 2 P0AAK1 HYCB_ECOLI hycB http://ecmdb.ca/proteins/P0AAK1.xml Hydrogenase-1 large chain P0ACD8 MBHL_ECOLI hyaB http://ecmdb.ca/proteins/P0ACD8.xml Hydrogenase-2 large chain P0ACE0 MBHM_ECOLI hybC http://ecmdb.ca/proteins/P0ACE0.xml Formate hydrogenlyase subunit 5 P16431 HYCE_ECOLI hycE http://ecmdb.ca/proteins/P16431.xml Formate hydrogenlyase subunit 6 P16432 HYCF_ECOLI hycF http://ecmdb.ca/proteins/P16432.xml Formate hydrogenlyase subunit 7 P16433 HYCG_ECOLI hycG http://ecmdb.ca/proteins/P16433.xml Hydrogenase-1 small chain P69739 MBHS_ECOLI hyaA http://ecmdb.ca/proteins/P69739.xml Hydrogenase-2 small chain P69741 MBHT_ECOLI hybO http://ecmdb.ca/proteins/P69741.xml Hydrogenase-4 component J P77453 HYFJ_ECOLI hyfJ http://ecmdb.ca/proteins/P77453.xml Hydrogenase-4 component D P77416 HYFD_ECOLI hyfD http://ecmdb.ca/proteins/P77416.xml Hydrogenase-4 component G P77329 HYFG_ECOLI hyfG http://ecmdb.ca/proteins/P77329.xml Probable Ni/Fe-hydrogenase 1 B-type cytochrome subunit P0AAM1 CYBH_ECOLI hyaC http://ecmdb.ca/proteins/P0AAM1.xml Hydrogenase-4 component F P77437 HYFF_ECOLI hyfF http://ecmdb.ca/proteins/P77437.xml Hydrogenase-2 operon protein hybA P0AAJ8 HYBA_ECOLI hybA http://ecmdb.ca/proteins/P0AAJ8.xml Hydrogenase-4 component E P0AEW1 HYFE_ECOLI hyfE http://ecmdb.ca/proteins/P0AEW1.xml Probable Ni/Fe-hydrogenase 2 b-type cytochrome subunit P37180 HYBB_ECOLI hybB http://ecmdb.ca/proteins/P37180.xml Hydrogenase-4 component C P77858 HYFC_ECOLI hyfC http://ecmdb.ca/proteins/P77858.xml Hydrogenase-4 component I P77668 HYFI_ECOLI hyfI http://ecmdb.ca/proteins/P77668.xml Hydrogenase-4 component B P23482 HYFB_ECOLI hyfB http://ecmdb.ca/proteins/P23482.xml Formate hydrogenlyase subunit 3 P16429 HYCC_ECOLI hycC http://ecmdb.ca/proteins/P16429.xml Hydrogenase-4 component H P77423 HYFH_ECOLI hyfH http://ecmdb.ca/proteins/P77423.xml Hydrogenase-4 component A P23481 HYFA_ECOLI hyfA http://ecmdb.ca/proteins/P23481.xml Formate hydrogenlyase subunit 4 P16430 HYCD_ECOLI hycD http://ecmdb.ca/proteins/P16430.xml Galactose-proton symporter P0AEP1 GALP_ECOLI galP http://ecmdb.ca/proteins/P0AEP1.xml Melibiose carrier protein P02921 MELB_ECOLI melB http://ecmdb.ca/proteins/P02921.xml H(+)/Cl(-) exchange transporter ClcA B1XD25 CLCA_ECODH clcA http://ecmdb.ca/proteins/B1XD25.xml Threonine/serine transporter tdcC C4ZR30 TDCC_ECOBW tdcC http://ecmdb.ca/proteins/C4ZR30.xml H(+)/Cl(-) exchange transporter ClcA C4ZRP8 CLCA_ECOBW clcA http://ecmdb.ca/proteins/C4ZRP8.xml Threonine/serine transporter tdcC P0AAD8 TDCC_ECOLI tdcC http://ecmdb.ca/proteins/P0AAD8.xml Arabinose-proton symporter P0AE24 ARAE_ECOLI araE http://ecmdb.ca/proteins/P0AE24.xml D-xylose-proton symporter P0AGF4 XYLE_ECOLI xylE http://ecmdb.ca/proteins/P0AGF4.xml Proline/betaine transporter P0C0L7 PROP_ECOLI proP http://ecmdb.ca/proteins/P0C0L7.xml H(+)/Cl(-) exchange transporter ClcA P37019 CLCA_ECOLI clcA http://ecmdb.ca/proteins/P37019.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 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 2 Hydrogen ion + Hydrogen (gas) + Ubiquinone-8 > Ubiquinol-8 +2 Hydrogen ion 2-Demethylmenaquinone 8 + 2 Hydrogen ion + Hydrogen (gas) > 2-Demethylmenaquinol 8 +2 Hydrogen ion 2 Hydrogen ion + Hydrogen (gas) + Menaquinone 8 > Menaquinol 8 +2 Hydrogen ion Formic acid + Hydrogen ion > Carbon dioxide + Hydrogen (gas) FHLMULTI-RXN Water + Phosphonate > Hydrogen (gas) + Phosphate Hydrogen ion + Formic acid > Carbon dioxide + Hydrogen (gas) FHLMULTI-RXN Hydrogen ion > Hydrogen (gas) RXN0-3283 a menaquinone + Hydrogen ion + Hydrogen (gas) > a menaquinol + Hydrogen ion RXN0-5256 Hydrogen (gas) + A > AH(2) Hydrogen (gas) + Acceptor <> Reduced acceptor R07182