2.02012-05-31 14:03:13 -06002015-09-17 15:42:01 -0600ECMDB04044M2MDB0005772-Dehydro-3-deoxy-D-galactonate2-Dehydro-3-deoxy-D-galactonate is a carbohydrate acid. It is an intermediate in carbohydrate-acid metabolism and D-galactonate metabolism. It is a substrate for 2-dehydro-3-deoxygalactonokinase which catalyzes the following reaction: ATP + 2-dehydro-3-deoxy-D-galactonate = ADP + 2-dehydro-3-deoxy-D-galactonate 6-phosphate.2-Dehydro-3-deoxy-D-galactonic acid2-Dehydro-3-deoxygalactonate2-Dehydro-3-deoxygalactonic acid2-Keto-3-deoxy-D-galactonate2-Keto-3-deoxy-D-galactonic acid2-Keto-3-deoxygalactonate2-Keto-3-deoxygalactonic acidC6H9O6177.133177.04046159(4R,5R)-4,5,6-trihydroxy-2-oxohexanoic acid(4R,5R)-4,5,6-trihydroxy-2-oxohexanoic acidOCC(O)C(O)CC(=O)C([O-])=OInChI=1S/C6H10O6/c7-2-5(10)3(8)1-4(9)6(11)12/h3,5,7-8,10H,1-2H2,(H,11,12)/p-1WPAMZTWLKIDIOP-UHFFFAOYSA-MCytosollogp-1.87logs-0.12solubility1.34e+02 g/llogp-1.8pka_strongest_acidic2.91pka_strongest_basic-3iupac(4R,5R)-4,5,6-trihydroxy-2-oxohexanoic acidaverage_mass177.133mono_mass177.04046159smilesOCC(O)C(O)CC(=O)C([O-])=OformulaC6H9O6inchiInChI=1S/C6H10O6/c7-2-5(10)3(8)1-4(9)6(11)12/h3,5,7-8,10H,1-2H2,(H,11,12)/p-1inchikeyWPAMZTWLKIDIOP-UHFFFAOYSA-Mpolar_surface_area115.06refractivity36.32polarizability15.54rotatable_bond_count5acceptor_count6donor_count4physiological_charge-1formal_charge0Galactose metabolismGalactose can be synthesized through two pathways: melibiose degradation involving an alpha galactosidase and lactose degradation involving a beta galactosidase. Melibiose is first transported inside the cell through the melibiose:Li+/Na+/H+ symporter. Once inside the cell, melibiose is degraded through alpha galactosidase into an alpha-D-galactose and a beta-D-glucose. The beta-D-glucose is phosphorylated by a glucokinase to produce a beta-D-glucose-6-phosphate which can spontaneously be turned into a alpha D glucose 6 phosphate. This alpha D-glucose-6-phosphate is metabolized into a glucose -1-phosphate through a phosphoglucomutase-1. The glucose -1-phosphate is transformed into a uridine diphosphate glucose through UTP--glucose-1-phosphate uridylyltransferase. The product, uridine diphosphate glucose, can undergo a reversible reaction in which it can be turned into uridine diphosphategalactose through an UDP-glucose 4-epimerase.
Galactose can also be produced by lactose degradation involving a lactose permease to uptake lactose from the environment and a beta-galactosidase to turn lactose into Beta-D-galactose.
Beta-D-galactose can also be uptaken from the environment through a galactose proton symporter.
Galactose is degraded through the following process:
Beta-D-galactose is introduced into the cytoplasm through a galactose proton symporter, or it can be synthesized from an alpha lactose that is introduced into the cytoplasm through a lactose permease. Alpha lactose interacts with water through a beta-galactosidase resulting in a beta-D-glucose and beta-D-galactose. Beta-D-galactose is isomerized into D-galactose. D-Galactose undergoes phosphorylation through a galactokinase, hence producing galactose 1 phosphate. On the other side of the pathway, a gluose-1-phosphate (product of the interaction of alpha-D-glucose 6-phosphate with a phosphoglucomutase resulting in a alpha-D-glucose-1-phosphate, an isomer of Glucose 1-phosphate, or an isomer of Beta-D-glucose 1-phosphate) interacts with UTP and a hydrogen ion in order to produce a uridine diphosphate glucose. This is followed by the interaction of galactose-1-phosphate with an established amount of uridine diphosphate glucose through a galactose-1-phosphate uridylyltransferase, which in turn output a glucose-1-phosphate and a uridine diphosphate galactose. The glucose -1-phosphate is transformed into a uridine diphosphate glucose through UTP--glucose-1-phosphate uridylyltransferase. The product, uridine diphosphate glucose, can undergo a reversible reaction in which it can be turned into uridine diphosphategalactose through an UDP-glucose 4-epimerase, and so the cycle can keep going as long as more lactose or galactose is imported into the cell
PW000821ec00052MetabolicMicrobial metabolism in diverse environmentsec01120Metabolic pathwayseco01100Galactitol and galactonate degradationD-galactonate can serve as the sole source of carbon and energy for E. coli . The initial step, after the transport of galactonic acid into the cell is the degradation of D-galactonate is dehydration to 2-dehydro-3-deoxy-D-galactonate by D-galactonate dehydratase. Subsequent phosphorylation by 2-dehydro-3-deoxygalactonate kinase and aldol cleavage by 2-oxo-3-deoxygalactonate 6-phosphate aldolase produce pyruvate and D-glyceraldehyde-3-phosphate, which enter central metabolism.
Galactitol can also be utilized by E. coli K-12 as a total source of carbon and energy. Each enters the cell via a specific phosphotransferase system, so the first intracellular species is D-galactitol-1-phosphate or D-galactitol-6-phosphate, which are identical. This sugar alcohol phosphate becomes the substrate for a dehydrogenase that oxidizes its 2-alcohol group to a keto group. Galactitol-1-phosphate, the product of the dehydrogenation is tagatose-6-phosphate, which becomes the substrate of a kinase and subsequently an aldolase (in a pair of reactions that parallel those of glycolysis) before it is converted into intermediates (D-glyceraldehde-3-phosphate and dihydroxy-acetone-phosphate) of glycolysis.PW000820Metabolichexuronide and hexuronate degradationE. coli can use β-D-glucuronosides, D-glucuronate and D-fructuronate as an only sources of carbon for growth.
β-D-glucuronosides are detoxification products that are excreted into the mammalian gut in the bile. They enter E.coli through an outer membrane protein called gusC. Once in the periplasmic space it is transported through a hydrogen symporter into the cytoplasm.
Once inside the cytoplasm, the initial step in the degradation of β-glucuronides is hydrolysis by β-D-glucuronidase to yield D-glucuronate. This is then isomerized to D-fructuronate by D-glucuronate isomerase. D-fructuronate then undergoes an NADH-dependent reduction to D-mannonate by D-mannonate oxidoreductase. D-mannonate dehydratase subsequently catalyzes dehydration to yield 2-dehydro-3-deoxy-D-gluconate. At this point, a common enzyme, 2-keto-3-deoxygluconokinase, phosphorylates 2-dehydro-3-deoxy-D-gluconate to yield 2-dehydro-3-deoxy-D-gluconate-6-phosphate.This product is then process by KHG/KDPG aldolase which in turn produces D-Glyceraldehyde 3-phosphate and Pyruvic Acid which then go into their respective sub pathways: glycolysis and pyruvate dehydrogenase
The pathway can also start from 3 other points: a hydrogen ion symporter (gluconate/fructuronate transporter GntP) of D-fructuronate, a hydrogen ion symporter (Hexuronate transporter) of aldehydo-D-galacturonate that spontaneously turns into D-tagaturonate and then undergoes an NADH-dependent reduction to D-altronate through an altronate oxidoreductase. D-altronate undergoes dehydration to yield 2-dehydro-3-deoxy-D-gluconate, the third and last point where the reaction can start from a hydrogen symporter of a 2-dehydro-3-deoy-D-gluconate.PW000834Metabolicinner membrane transportlist of inner membrane transport complexes, transporting compounds from the periplasmic space to the cytosol
This pathway should be updated regularly with the new inner membrae transports addedPW000786MetabolicD-galactonate degradationGALACTCAT-PWYSpecdb::CMs17516Specdb::CMs38037Specdb::CMs135041Specdb::CMs142775Specdb::NmrOneD87792Specdb::NmrOneD87793Specdb::NmrOneD87794Specdb::NmrOneD87795Specdb::NmrOneD87796Specdb::NmrOneD87797Specdb::NmrOneD87798Specdb::NmrOneD87799Specdb::NmrOneD87800Specdb::NmrOneD87801Specdb::NmrOneD87802Specdb::NmrOneD87803Specdb::NmrOneD87804Specdb::NmrOneD87805Specdb::NmrOneD87806Specdb::NmrOneD87807Specdb::NmrOneD87808Specdb::NmrOneD87809Specdb::NmrOneD87810Specdb::NmrOneD87811Specdb::MsMs25415Specdb::MsMs25416Specdb::MsMs25417Specdb::MsMs31973Specdb::MsMs31974Specdb::MsMs31975Specdb::MsMs2475047Specdb::MsMs2475048Specdb::MsMs2475049Specdb::MsMs2490845Specdb::MsMs2490846Specdb::MsMs24908473736C01216170282-DEHYDRO-3-DEOXY-D-GALACTONATEKeseler, 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 370:17-25.177651952-dehydro-3-deoxygalactonokinaseP31459DGOK_ECOLIdgoKhttp://ecmdb.ca/proteins/P31459.xmlD-galactonate dehydrataseQ6BF17DGOD_ECOLIdgoDhttp://ecmdb.ca/proteins/Q6BF17.xml2-Dehydro-3-deoxy-D-galactonate + Adenosine triphosphate <> 2-Dehydro-3-deoxy-D-galactonate-6-phosphate + ADP + Hydrogen ionR03387DEHYDDEOXGALACTKIN-RXNGalactonic acid <> 2-Dehydro-3-deoxy-D-galactonate + WaterR03033Adenosine triphosphate + 2-Dehydro-3-deoxy-D-galactonate <> ADP + 2-Dehydro-3-deoxy-D-galactonate-6-phosphateR033872-Dehydro-3-deoxy-D-galactonate + Adenosine triphosphate > Hydrogen ion + 2-Dehydro-3-deoxy-D-galactonate-6-phosphate + ADPDEHYDDEOXGALACTKIN-RXND-Galactonate > Water + 2-Dehydro-3-deoxy-D-galactonateGALACTONDEHYDRAT-RXNGalactonic acid > 2-Dehydro-3-deoxy-D-galactonate + WaterAdenosine triphosphate + 2-Dehydro-3-deoxy-D-galactonate > ADP + 2-Dehydro-3-deoxy-D-galactonate 6-phosphate D-altronate > Water + 2-Dehydro-3-deoxy-D-galactonate + 2-Keto-3-deoxy-D-gluconic acidPW_R003060 D-altronate + D-altronate > Water + 2-Dehydro-3-deoxy-D-galactonate + 2-Keto-3-deoxy-D-gluconic acidPW_R0030612-Dehydro-3-deoxy-D-galactonate + Adenosine triphosphate + 2-Keto-3-deoxy-D-gluconic acid > Hydrogen ion + 2-Keto-3-deoxy-6-phosphogluconic acid + Adenosine diphosphate + ADPPW_R003064Galactonic acid + Galactonic acid > Water + 2-dehydro-3-deoxy-D-galactonate + 2-Dehydro-3-deoxy-D-galactonatePW_R0029402-dehydro-3-deoxy-D-galactonate + Adenosine triphosphate + 2-Dehydro-3-deoxy-D-galactonate > Adenosine diphosphate + Hydrogen ion + 2-dehydro-3-deoxy-D-galactonate 6-phosphate + ADP + 2-Dehydro-3-deoxy-D-galactonate 6-phosphatePW_R002941