2.0 2012-05-31 14:08:43 -0600 2015-09-17 15:41:19 -0600 ECMDB06511 M2MDB000677 2,3-Diketo-L-gulonate 2,3-Diketo-L-gulonate is an intermediate in Ascorbate and aldarate metabolism. 2,3-Diketo-L-gulonate is produced from Dehydroascorbate and then converted to L-Xylonate via the enzyme Lyases (EC 4.1.1.-). (4R,5S)-4,5,6-Trihydroxy-2,3-dioxohexanoate (4R,5S)-4,5,6-Trihydroxy-2,3-dioxohexanoic acid 2,3-Diketo-L gulonate 2,3-Diketo-L gulonic acid 2,3-Diketo-L-gulonate 2,3-Diketo-L-gulonic acid 2,3-Diketogulonate 2,3-Diketogulonic acid Diketogulonate Diketogulonic acid DKG L-Threo-2,3-hexodiulosonate L-Threo-2,3-hexodiulosonic acid L-Threo-hexo-2,3-diulosonate L-Threo-hexo-2,3-diulosonic acid L-Xylo-hex-2-enonate L-Xylo-hex-2-enonic acid C6H8O7 192.1235 192.02700261 (4S,5S)-4,5,6-trihydroxy-2,3-dioxohexanoic acid (4S,5S)-4,5,6-trihydroxy-2,3-dioxohexanoic acid OC[C@H](O)C(O)C(=O)C(=O)C(O)=O InChI=1S/C6H8O7/c7-1-2(8)3(9)4(10)5(11)6(12)13/h2-3,7-9H,1H2,(H,12,13)/t2-,3?/m0/s1 GJQWCDSAOUMKSE-SCQFTWEKSA-N Solid Cytosol logp -1.77 ALOGPS logs -0.51 ALOGPS solubility 5.99e+01 g/l ALOGPS logp -1.6 ChemAxon pka_strongest_acidic 2.38 ChemAxon pka_strongest_basic -3 ChemAxon iupac (4S,5S)-4,5,6-trihydroxy-2,3-dioxohexanoic acid ChemAxon average_mass 192.1235 ChemAxon mono_mass 192.02700261 ChemAxon smiles OC[C@H](O)C(O)C(=O)C(=O)C(O)=O ChemAxon formula C6H8O7 ChemAxon inchi InChI=1S/C6H8O7/c7-1-2(8)3(9)4(10)5(11)6(12)13/h2-3,7-9H,1H2,(H,12,13)/t2-,3?/m0/s1 ChemAxon inchikey GJQWCDSAOUMKSE-SCQFTWEKSA-N ChemAxon polar_surface_area 132.13 ChemAxon refractivity 37.04 ChemAxon polarizability 15.25 ChemAxon rotatable_bond_count 5 ChemAxon acceptor_count 7 ChemAxon donor_count 4 ChemAxon physiological_charge -1 ChemAxon formal_charge 0 ChemAxon Ascorbate and aldarate metabolism ec00053 Pentose and glucuronate interconversions ec00040 Ascorbate metabolism E. coli is able to utilize L-ascorbate (vitamin C) as the sole source of carbon under anaerobic and aerobic conditions. Ascorbic acid in the cytoplasm is processed through a spontaneous reaction with a hydrogen ion and hydrogen peroxide, producing water, dehydroascorbic acid and ascorbic acid. Dehydroascorbic acid reacts with water spontaneously producing an isomer, dehydroascorbate (bicyclic form). The compound then loses a hydrogen ion resulting in a 2,3-Diketo-L-gulonate. This compound is then reduced through a NADH dependent 2,3 diketo-L-gulonate reductase, releasing a NAD and 3-Dehydro-L-gulonate.This compound is phosphorylated through an ATP mediated L-xylulose/3-keto-L-gulonate kinase resulting in an ADP, hydrogen ion and a 3-Keto-L-gulonate 6 phosphate. L-ascorbate can also be imported and converted to L-ascorbate-6-phosphate by the L-ascorbate PTS transporter. L-ascorbate-6-phosphate reacts with a probable L-ascorbate-6-phosphate lactonase ulaG, resulting in a 3-keto-L-gulonate 6-phosphate. The compound 3-keto-L-gulonate 6-phosphate can be processed aerobically or anaerobically. Aerobic: 3-keto-L-gulonate 6-phosphate is decarboxylated by a 3-keto-L-gulonate-6-phosphate decarboxylase ulaD, releasing carbon dioxide and L-xylulose-5-phosphate. This compound in turn is changed into an isomer by L-ribulose-5-phosphate 3-epimerase ulaE, resulting in L-ribulose 5-phosphate. This compound again changes into a different isomer through a L-ribulose-5-phosphate 4-epimerase ulaF resulting in Xylulose 5-phosphate. This compound can then be part of the pentose phosphate pathway. Anaerobic: 3-keto-L-gulonate 6-phosphate is decarboxylated by 3-keto-L-gulonate 6-phosphate decarboxylase sgbH, releasing carbon dioxide and L-xylulose-5-phosphate. This compound in turn is changed into an isomer by predicted L-xylulose 5-phosphate 3-epimerase, resulting in L-ribulose 5-phosphate. This compound again changes into a different isomer through a L-ribulose-5-phosphate 4-epimerase resulting in Xylulose 5-phosphate. This compound can then be part of the pentose phosphate pathway. Expression of the ula regulon is regulated by the L-ascorbate 6-phosphate-binding repressor UlaR and by cAMP-CRP. Under aerobic conditions, metabolism of L-ascorbate is hindered by the special reactivity and toxicity of this compound in the presence of oxygen. PW000793 Metabolic L-ascorbate degradation II (bacterial, aerobic) PWY-6961 Specdb::MsMs 24860 Specdb::MsMs 24861 Specdb::MsMs 24862 Specdb::MsMs 31418 Specdb::MsMs 31419 Specdb::MsMs 31420 HMDB06511 440390 C04575 15622 CPD-334 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 van 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. 17765195 2,3-diketo-L-gulonate reductase P37672 DLGD_ECOLI dlgD http://ecmdb.ca/proteins/P37672.xml 3-keto-L-gulonate-6-phosphate decarboxylase sgbH P37678 SGBH_ECOLI sgbH http://ecmdb.ca/proteins/P37678.xml 2,3-diketo-L-gulonate TRAP transporter small permease protein yiaM P37674 YIAM_ECOLI yiaM http://ecmdb.ca/proteins/P37674.xml 2,3-diketo-L-gulonate TRAP transporter large permease protein yiaN P37675 YIAN_ECOLI yiaN http://ecmdb.ca/proteins/P37675.xml 2,3-Diketo-L-gulonate + Hydrogen ion + NADH > 3-Dehydro-L-gulonate + NAD R02637 RXN0-703 3-Dehydro-L-gulonate + NAD <> 2,3-Diketo-L-gulonate + NADH + Hydrogen ion R02637 3-Dehydro-L-gulonate + NADP <> 2,3-Diketo-L-gulonate + NADPH + Hydrogen ion R02639 dehydroascorbate (bicyclic form) > 2,3-Diketo-L-gulonate + Hydrogen ion RXN-12861 2,3-Diketo-L-gulonate > 2-carboxy-L-xylonolactone RXN-12870 3-Dehydro-L-gulonate + NAD < Hydrogen ion + 2,3-Diketo-L-gulonate + NADH RXN0-703 3-Dehydro-L-gulonate + NAD + NADP <> 2,3-Diketo-L-gulonate + NADH + NADPH + Hydrogen ion R02637 R02639 2,3-Diketo-L-gulonate + NADH + Hydrogen ion + 2,3-Diketo-L-gulonate > 3-Dehydro-L-gulonate + NAD PW_R002698 2,3-Diketo-L-gulonate + Hydrogen ion + 2,3-Diketo-L-gulonate > Carbon dioxide + Xylulose 5-phosphate + Xylulose 5-phosphate PW_R002704