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Escherichia coli K-12 substr. MG1655 Pathway: glyoxylate cycle
Inferred from experiment

Pathway diagram: glyoxylate cycle

If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Locations of Mapped Genes:

Schematic showing all replicons, marked with selected genes

Genetic Regulation Schematic

Genetic regulation schematic for glyoxylate cycle

Synonyms: glyoxylate bypass, glyoxylate shunt

Superclasses: Generation of Precursor Metabolites and Energy

The glyoxylate cycle is a sequence of anaplerotic reactions that enables an organism to use substrates that enter central carbon metabolism at the level of acetyl-CoA as the sole carbon source. Such substrates include fatty acids, alcohols, and esters (often the products of fermentation), as well as waxes, alkenes, and methylated compounds.

The pathway is essentially a modified version of the TCA cycle I (prokaryotic) that bypasses those steps in the cycle that lead to a loss of CO2. The glyoxylate cycle uses a two-step bypass. The first key enzyme, isocitrate lyase (EC, converts D-threo-isocitrate to form succinate and glyoxylate. The second key enzyme, malate synthase A (EC, condenses glyoxylate and another molecule of acetyl-CoA to form (S)-malate. The subsequent oxidation of malate regenerates the initial acetyl-CoA acceptor molecule of the TCA cycle, oxaloacetate. In this way any intermediate of the TCA cycle can be withdrawn from the cycle and used for cell carbon biosynthesis.

In Escherichia coli the pathway is active when growth on two-carbon compounds requires conservation of four-carbon TCA intermediates. Two acetyl-CoA are taken up per turn. The glyoxylate cycle is repressed during growth on glucose and induced by growth on acetate [Cortay89, Walsh84, LaPorte84, Nimmo84].

Acetyl-CoA is generated by acetate conversion to acetyl-CoA or by β oxidation of fatty acids.

Superpathways: superpathway of glyoxylate bypass and TCA, superpathway of glycolysis, pyruvate dehydrogenase, TCA, and glyoxylate bypass

Revised 04-Dec-2007 by Caspi R, SRI International


Cortay89: Cortay JC, Bleicher F, Duclos B, Cenatiempo Y, Gautier C, Prato JL, Cozzone AJ (1989). "Utilization of acetate in Escherichia coli: structural organization and differential expression of the ace operon." Biochimie 71(9-10):1043-1049. PMID: 2512996

LaPorte84: LaPorte DC, Walsh K, Koshland DE (1984). "The branch point effect. Ultrasensitivity and subsensitivity to metabolic control." J Biol Chem 1984;259(22);14068-75. PMID: 6389540

Nimmo84: Nimmo GA, Nimmo HG (1984). "The regulatory properties of isocitrate dehydrogenase kinase and isocitrate dehydrogenase phosphatase from Escherichia coli ML308 and the roles of these activities in the control of isocitrate dehydrogenase." Eur J Biochem 1984;141(2);409-14. PMID: 6329757

Walsh84: Walsh K, Koshland DE (1984). "Determination of flux through the branch point of two metabolic cycles. The tricarboxylic acid cycle and the glyoxylate shunt." J Biol Chem 1984;259(15);9646-54. PMID: 6378912

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Al12: Al Mamun AA, Lombardo MJ, Shee C, Lisewski AM, Gonzalez C, Lin D, Nehring RB, Saint-Ruf C, Gibson JL, Frisch RL, Lichtarge O, Hastings PJ, Rosenberg SM (2012). "Identity and function of a large gene network underlying mutagenic repair of DNA breaks." Science 338(6112);1344-8. PMID: 23224554

Amarneh05: Amarneh B, Vik SB (2005). "Direct transfer of NADH from malate dehydrogenase to complex I in Escherichia coli." Cell Biochem Biophys 42(3);251-61. PMID: 15976458

Anderson88: Anderson DH, Duckworth HW (1988). "In vitro mutagenesis of Escherichia coli citrate synthase to clarify the locations of ligand binding sites." J Biol Chem 1988;263(5);2163-9. PMID: 3276685

Anstrom03: Anstrom DM, Kallio K, Remington SJ (2003). "Structure of the Escherichia coli malate synthase G:pyruvate:acetyl-coenzyme A abortive ternary complex at 1.95 A resolution." Protein Sci 12(9);1822-32. PMID: 12930982

Bennett95: Bennett B, Gruer MJ, Guest JR, Thomson AJ (1995). "Spectroscopic characterisation of an aconitase (AcnA) of Escherichia coli." Eur J Biochem 233(1);317-26. PMID: 7588761

Blank02: Blank L, Green J, Guest JR (2002). "AcnC of Escherichia coli is a 2-methylcitrate dehydratase (PrpD) that can use citrate and isocitrate as substrates." Microbiology 148(Pt 1);133-46. PMID: 11782506

Bradbury96: Bradbury AJ, Gruer MJ, Rudd KE, Guest JR (1996). "The second aconitase (AcnB) of Escherichia coli." Microbiology 142 ( Pt 2);389-400. PMID: 8932712

BRENDA14: BRENDA team (2014). Imported from BRENDA version existing on Aug 2014.

Brock02: Brock M, Maerker C, Schutz A, Volker U, Buckel W (2002). "Oxidation of propionate to pyruvate in Escherichia coli. Involvement of methylcitrate dehydratase and aconitase." Eur J Biochem 269(24);6184-94. PMID: 12473114

Calderon09: Calderon IL, Elias AO, Fuentes EL, Pradenas GA, Castro ME, Arenas FA, Perez JM, Vasquez CC (2009). "Tellurite-mediated disabling of [4Fe-4S] clusters of Escherichia coli dehydratases." Microbiology 155(Pt 6);1840-6. PMID: 19383690

Courtright70: Courtright JB, Henning U (1970). "Malate dehydrogenase mutants in Escherichia coli K-12." J Bacteriol 102(3);722-8. PMID: 4914076

Creaghan78: Creaghan IT, Guest JR (1978). "Succinate dehydrogenase-dependent nutritional requirement for succinate in mutants of Escherichia coli K12." J Gen Microbiol 107(1);1-13. PMID: 366070

Cunningham97: Cunningham L, Gruer MJ, Guest JR (1997). "Transcriptional regulation of the aconitase genes (acnA and acnB) of Escherichia coli." Microbiology 143 ( Pt 12);3795-805. PMID: 9421904

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Duckworth87: Duckworth HW, Anderson DH, Bell AW, Donald LJ, Chu AL, Brayer GD (1987). "Structural basis for regulation in gram-negative bacterial citrate synthases." Biochem Soc Symp 1987;54;83-92. PMID: 3333000

Else88: Else AJ, Danson MJ, Weitzman PD (1988). "Models of proteolysis of oligomeric enzymes and their applications to the trypsinolysis of citrate synthases." Biochem J 1988;254(2);437-42. PMID: 3140803

Falmagne65: Falmagne P, Vanderwinkel E, Wiame JM (1965). "Mise en evidence de deux malate synthases chez E. coli." BBActa 1965;99:246-258. PMID: 14336062

Falmagne73: Falmagne P, Wiame JM (1973). "[Purification and partial characterization of two malate synthases of Echerichia coli]." Eur J Biochem 37(3);415-24. PMID: 4591144

Fernley81: Fernley RT, Lentz SR, Bradshaw RA (1981). "Malate dehydrogenase: isolation from E. coli and comparison with the eukaryotic mitochondrial and cytoplasmic forms." Biosci Rep 1(6);497-507. PMID: 7028159

Gaudet10: Gaudet P, Livstone M, Thomas P (2010). "Annotation inferences using phylogenetic trees." PMID: 19578431

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by Pathway Tools version 19.5 (software by SRI International) on Mon May 2, 2016, biocyc14.