2.02012-05-31 14:53:48 -06002015-09-17 15:41:50 -0600ECMDB20620M2MDB001418Ubiquinone-6Ubiquinone-6 is a member of the chemical class known as Polyprenylbenzoquinones. These are compounds containing a polyisoprene chain attached to a quinone at the second ring position. Ubiquione-6 has just 6 isoprene units. Normally in E. coli the active form of Ubiquinone has 8 isoprene units (Ubiquinone-8) and in humans it normally has 10. Ubiquinone-6 is a “failed” or incomplete version of Ubiquinone 8 that arises from conjugation by a shortened prenyl tail via 4-hydroxybenzoate polyprenyltransferase. Ubiquionone is involved in cellular respiration. It is fat-soluble and is therefore mobile in cellular membranes; it plays a unique role in the electron transport chain (ETC). In the inner bacterial membrane, electrons from NADH and succinate pass through the ETC to the oxygen, which is then reduced to water. The transfer of electrons through ETC results in the pumping of H+ across the membrane creating a proton gradient across the membrane, which is used by ATP synthase (located on the membrane) to generate ATP.C9504_SIGMACoenzyme Q6Coenzyme Qq6Coenzyme-?Q6Coenzyme-Q6Coenzyme-Q<SUB>6</SUB>CoQ-6CoQ6Q6Ubiquinone 30Ubiquinone 6Ubiquinone Q6Ubiquinone(30)Ubiquinone(6)Ubiquinone-30C39H58O4590.8754590.4335103442-[(2E,6E,10E,14E,18E)-3,7,11,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaen-1-yl]-5,6-dimethoxy-3-methylcyclohexa-2,5-diene-1,4-dioneubiquinone 61065-31-2COC1=C(OC)C(=O)C(CC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)C)=C(C)C1=OInChI=1S/C39H58O4/c1-28(2)16-11-17-29(3)18-12-19-30(4)20-13-21-31(5)22-14-23-32(6)24-15-25-33(7)26-27-35-34(8)36(40)38(42-9)39(43-10)37(35)41/h16,18,20,22,24,26H,11-15,17,19,21,23,25,27H2,1-10H3GXNFPEOUKFOTKY-UHFFFAOYSA-NInner membraneMembraneOuter membranelogp8.41logs-6.26solubility3.25e-04 g/llogp10.52pka_strongest_basic-4.7iupac2-[(2E,6E,10E,14E,18E)-3,7,11,15,19,23-hexamethyltetracosa-2,6,10,14,18,22-hexaen-1-yl]-5,6-dimethoxy-3-methylcyclohexa-2,5-diene-1,4-dioneaverage_mass590.8754mono_mass590.433510344smilesCOC1=C(OC)C(=O)C(CC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)CCC=C(C)C)=C(C)C1=OformulaC39H58O4inchiInChI=1S/C39H58O4/c1-28(2)16-11-17-29(3)18-12-19-30(4)20-13-21-31(5)22-14-23-32(6)24-15-25-33(7)26-27-35-34(8)36(40)38(42-9)39(43-10)37(35)41/h16,18,20,22,24,26H,11-15,17,19,21,23,25,27H2,1-10H3inchikeyGXNFPEOUKFOTKY-UHFFFAOYSA-Npolar_surface_area52.6refractivity191.39polarizability73.44rotatable_bond_count19acceptor_count4donor_count0physiological_charge0formal_charge0Ubiquinone and other terpenoid-quinone biosynthesisec00130TCA cycle (ubiquinol-6)The TCA pathway is a catabolic pathway of aerobic respiration. It generates energy and reducing power. It is the first step in generating precursors for biosynthesis. When acetate is the carbon source, citrate synthase is rate-limiting for the TCA cycle. Respiration is an ATP-generating process in which compounds act as electron donors through a chain of electron transfer to electron acceptors. Aerobic respiration uses oxygen as the final acceptor. Anaerobic respiration uses several organic compounds as acceptors such as fumarate, nitrate and hydrogen. During the chain of electron transfer, protons (H+) are transported outside the cytoplasmic membrane, generating a proton motive force. Upon passage of protons back into the cytoplasm, the PMF energy is captured as ATP, catalyzed by a multisubunit ATPase.
The cycle can start from Acetyl-CoA interacting with Oxalacetic acid and water through a citrate synthase monomer resulting in a hydrogen ion, CoA and a Citric Acid. The latter compound is dehydrated by a Citrate hydro-lyase resulting in the release of water and a cis-Aconitic acid. This compound is then hydrated through a Citrate hydro-lyase resulting in a D-threo-Isocitric acid. This compound is decarboxylated by an NADP dependent Citrate dehydrogenase, resulting in a release of carbon dioxide and NADPH and Oxoglutaric acid. The oxoglutaric acid interacts with a Coenzyme A through a NAD driven 2-oxoglutarate dehydrogenase resulting in a release of carbon dioxide, an NADH and succinyl-CoA. The succinyl-CoA interacts with a phosphate and an ADP through a 2-oxoglutarate dehydrogenase resulting in a CoA, an ATP and Succinic Acid. Succinic acid interacts with a ubiquinone, in this case a ubiquinone 1 through a succinate:quinone oxidoreductase resulting in an ubiquinol, in this case a ubiquinol-1 and a fumaric acid.
The fumaric acid interacts with water through a fumarase hydratase resulting in a L-Malic acid.This compound can either interact with quinone through a malate:quinone oxidoreductase resulting in a release of hydroquinone and oxalacetic acid, or it can react with an NAD through a malate dehydrogenase resulting in a hydrogen ion, NADH and Oxalacetic acid.PW001006MetabolicSpecdb::NmrOneD260568Specdb::NmrOneD260569Specdb::NmrOneD260570Specdb::NmrOneD260571Specdb::NmrOneD260572Specdb::NmrOneD260573Specdb::NmrOneD260574Specdb::NmrOneD260575Specdb::NmrOneD260576Specdb::NmrOneD260577Specdb::NmrOneD260578Specdb::NmrOneD260579Specdb::NmrOneD260580Specdb::NmrOneD260581Specdb::NmrOneD260582Specdb::NmrOneD260583Specdb::NmrOneD260584Specdb::NmrOneD260585Specdb::NmrOneD260586Specdb::NmrOneD260587Specdb::MsMs103914Specdb::MsMs103915Specdb::MsMs103916Specdb::MsMs170082Specdb::MsMs170083Specdb::MsMs17008452835444446657C17568UBIQUINONE-6Keseler, 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-D114.22080510van der Werf, M. J., Overkamp, K. M., Muilwijk, B., Coulier, L., Hankemeier, T. (2007). "Microbial metabolomics: toward a platform with full metabolome coverage." Anal Biochem 370:17-25.17765195Winder, C. L., Dunn, W. B., Schuler, S., Broadhurst, D., Jarvis, R., Stephens, G. M., Goodacre, R. (2008). "Global metabolic profiling of Escherichia coli cultures: an evaluation of methods for quenching and extraction of intracellular metabolites." Anal Chem 80:2939-2948.18331064D-lactate dehydrogenaseP06149DLD_ECOLIdldhttp://ecmdb.ca/proteins/P06149.xmlSuccinate dehydrogenase iron-sulfur subunitP07014DHSB_ECOLIsdhBhttp://ecmdb.ca/proteins/P07014.xmlSuccinate dehydrogenase flavoprotein subunitP0AC41DHSA_ECOLIsdhAhttp://ecmdb.ca/proteins/P0AC41.xmlSuccinate dehydrogenase hydrophobic membrane anchor subunitP0AC44DHSD_ECOLIsdhDhttp://ecmdb.ca/proteins/P0AC44.xml3-demethylubiquinone-9 3-methyltransferaseP17993UBIG_ECOLIubiGhttp://ecmdb.ca/proteins/P17993.xmlSuccinate dehydrogenase cytochrome b556 subunitP69054DHSC_ECOLIsdhChttp://ecmdb.ca/proteins/P69054.xmlSuccinic acid + Ubiquinone-6 > Fumaric acid + Ubiquinol-6PW_R003749L-Lactic acid + Ubiquinone-6 > Pyruvic acid + Ubiquinol-6PW_R006151