2.0 2012-05-31 13:01:01 -0600 2015-06-03 15:53:35 -0600 ECMDB00751 M2MDB000183 L-Threo-2-pentulose L-Threo-2-pentulose, also called L-xylulose, is a ketopentose - a monosaccharide containing five carbon atoms, and including a ketone functional group. It has chemical formula C5H10O5. In nature it occurs in the L- and D- isomers. (Wikipedia) L-Xylulose C5H10O5 150.1299 150.05282343 (3R,4S)-1,3,4,5-tetrahydroxypentan-2-one xylulose 527-50-4 OC[C@H](O)[C@@H](O)C(=O)CO InChI=1S/C5H10O5/c6-1-3(8)5(10)4(9)2-7/h3,5-8,10H,1-2H2/t3-,5+/m0/s1 ZAQJHHRNXZUBTE-WVZVXSGGSA-N Solid Cytosol Extra-organism Periplasm logp -2.16 ALOGPS logs 0.65 ALOGPS solubility 6.78e+02 g/l ALOGPS logp -2.6 ChemAxon pka_strongest_acidic 10.57 ChemAxon pka_strongest_basic -3 ChemAxon iupac (3R,4S)-1,3,4,5-tetrahydroxypentan-2-one ChemAxon average_mass 150.1299 ChemAxon mono_mass 150.05282343 ChemAxon smiles OC[C@H](O)[C@@H](O)C(=O)CO ChemAxon formula C5H10O5 ChemAxon inchi InChI=1S/C5H10O5/c6-1-3(8)5(10)4(9)2-7/h3,5-8,10H,1-2H2/t3-,5+/m0/s1 ChemAxon inchikey ZAQJHHRNXZUBTE-WVZVXSGGSA-N ChemAxon polar_surface_area 97.99 ChemAxon refractivity 31.6 ChemAxon polarizability 13.5 ChemAxon rotatable_bond_count 4 ChemAxon acceptor_count 5 ChemAxon donor_count 4 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Ascorbate and aldarate metabolism ec00053 Pentose and glucuronate interconversions ec00040 L-lyxose Degradation L-lyxose is an uncommon sugar in nature, and wild-type E. coli can not utilize it as a sole source of carbon and energy. However, mutations can arise that allow E. coli to metabolize L-lyxose through the use of enzymes of the rhamnose, arabinose and 2,3-diketo-L-gulonate systems. L-lyxose enters the cell through the rhaT-encoded rhamnose transporter. It is then isomerized to L-xylulose by L-rhamnose isomerase. Two types of mutations then allow further utilization of L-xylulose. Not shown here, a mutated from of L-rhamnulose kinase can phosphorylate L-xylulose, yielding L-xylulose-1-phosphate. Further metabolism to dihydroxyacetone phosphate and glycolate occurs through the rhamnulose-1-phosphate aldolase and aldehyde dehydrogenase A, NAD-linked enzymes. These products can enter glycolate degradation and glycolysis. As shown here, L-xylulose can be phosphorylated by L-xylulose kinase in a mutant in which YiaJ, the repressor for the yiaKLMNO-lyxK-sgbHUE operon, has been disrupted. L-xylulose-5-phosphate is then further metabolized by predicted L-xylulose 5-phosphate 3-epimerase (so far only a predicted function) and either of two L-ribulose 5-phosphate 4-epimerases (SgbE or AraD) to D-xylulose-5-phosphate, which then enters the pentose phosphate pathway (non-oxidative branch). The enzymes of L-rhamnose degradation I and L-arabinose degradation I are inducible by L-lyxose as well. (EcoCyc) PW002100 Metabolic Xylose Degradation I D-xylose, which can serve as a total source of carbon and energy for Escherichia coli K-12 substr. MG1655, enters the cell either through a low-affinity, proton-motive force-driven or a high-affinity, ATP-driven (ABC) transport system, so it is not phosphorylated during entry. Once inside the cell, an isomerase converts it to D-xylulose and subsequently a kinase converts it to D-xylulose 5-phosphate, an intermediate of the pentose phosphate pathway. Hence it flows through the pathways of central metabolism to satisfy the cell's need for precursor metabolites, reducing power, and metabolic energy. (EcoCyc) PW002105 Metabolic Specdb::CMs 13703 Specdb::CMs 37743 Specdb::NmrOneD 306351 Specdb::NmrOneD 306352 Specdb::NmrOneD 306353 Specdb::NmrOneD 306354 Specdb::NmrOneD 306355 Specdb::NmrOneD 306356 Specdb::NmrOneD 306357 Specdb::NmrOneD 306358 Specdb::NmrOneD 306359 Specdb::NmrOneD 306360 Specdb::NmrOneD 306361 Specdb::NmrOneD 306362 Specdb::NmrOneD 306363 Specdb::NmrOneD 306364 Specdb::NmrOneD 306365 Specdb::NmrOneD 306366 Specdb::NmrOneD 306367 Specdb::NmrOneD 306368 Specdb::NmrOneD 306369 Specdb::NmrOneD 306370 Specdb::MsMs 29201 Specdb::MsMs 29202 Specdb::MsMs 29203 Specdb::MsMs 35759 Specdb::MsMs 35760 Specdb::MsMs 35761 HMDB00751 439205 20892 C00312 17399 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 Winder, 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. 18331064 Oka H, Suzuki S, Suzuki H, Oda T: Increased urinary excretion of L-xylulose in patients with liver cirrhosis. Clin Chim Acta. 1976 Mar 1;67(2):131-6. 1248150 Ashwell, Gilbert; Kanfer, Julian; Burns, J. J. Mechanism of L-xylulose formation by kidney enzymes. Journal of Biological Chemistry (1959), 234 472-5. Xylose isomerase P00944 XYLA_ECOLI xylA http://ecmdb.ca/proteins/P00944.xml Ribulokinase P08204 ARAB_ECOLI araB http://ecmdb.ca/proteins/P08204.xml Xylulose kinase P09099 XYLB_ECOLI xylB http://ecmdb.ca/proteins/P09099.xml L-rhamnose isomerase P32170 RHAA_ECOLI rhaA http://ecmdb.ca/proteins/P32170.xml Rhamnulokinase P32171 RHAB_ECOLI rhaB http://ecmdb.ca/proteins/P32171.xml L-xylulose/3-keto-L-gulonate kinase P37677 LYXK_ECOLI lyx http://ecmdb.ca/proteins/P37677.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-binding periplasmic protein yiaO P37676 YIAO_ECOLI yiaO http://ecmdb.ca/proteins/P37676.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 Adenosine triphosphate + L-Threo-2-pentulose <> ADP + Hydrogen ion + L-Xylulose 5-phosphate R01901 L-Lyxose > L-Threo-2-pentulose Adenosine triphosphate + L-Threo-2-pentulose <> ADP + L-Xylulose 5-phosphate R01901 Adenosine triphosphate + L-Threo-2-pentulose <> ADP + L-Xylulose 1-phosphate R01902 Adenosine triphosphate + L-Threo-2-pentulose > ADP + L-Xylulose 5-phosphate L-Threo-2-pentulose + Adenosine triphosphate + L-Threo-2-pentulose > Xylulose 5-phosphate + Adenosine diphosphate + Xylulose 5-phosphate + ADP PW_R003849 β-D-xylopyranose <> L-Threo-2-pentulose PW_R006134 L-Threo-2-pentulose + Adenosine triphosphate > Xylulose 5-phosphate + ADP + Hydrogen ion PW_R006135 L-Threo-2-pentulose + Adenosine triphosphate > L-Xylulose 5-phosphate + ADP + Hydrogen ion PW_R006125 β-L-lyxopyranose <> L-Threo-2-pentulose PW_R006124