Escherichia coli K-12 substr. MG1655 Pathway: galactitol degradation
Inferred from experiment

Pathway diagram: galactitol degradation

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 galactitol degradation

Synonyms: galactitol catabolism

Superclasses: Degradation/Utilization/AssimilationSecondary Metabolites DegradationSugar Derivatives DegradationSugar Alcohols Degradation

Of the six existing hexitols, only three (D-mannitol, D-sorbitol [glucitol], and galactitol [owing to symmetry, D- and L-galactitol are identical]) occur naturally, and each of these can 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 the 6-phospho-derivative (in the case of galactitol, D-galactitol-1-phosphate and D-galactitol-6-phosphate are identical). In all three cases, this sugar alcohol phosphate becomes the substrate for a dehydrogenase that oxidizes its 2-alcohol group to a keto group. In the cases of mannitol and sorbitol, the resulting keto sugar phosphate is D-fructose-6-phosphate, an intermediate of glycolysis and hence it flows through the pathways of central metabolism to satisfy the cell's need for precursor metabolites, reducing power, and metabolic energy. In the case of galactitol-1-phosphate, however, 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.

Review: Mayer, C. and W. Boos, Hexose/Pentose and Hexitol/Pentitol Metabolism. EcoSal Module 3.4.1 [ECOSAL]

Superpathways: superpathway of hexitol degradation (bacteria)

Created 14-Oct-1996 by Riley M, Marine Biological Laboratory
Revised 09-May-2006 by Ingraham JL, UC Davis


ECOSAL: "Escherichia coli and Salmonella: Cellular and Molecular Biology." Online edition.

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

Babul78: Babul J (1978). "Phosphofructokinases from Escherichia coli. Purification and characterization of the nonallosteric isozyme." J Biol Chem 1978;253(12);4350-5. PMID: 149128

Baez07: Baez M, Cabrera R, Guixe V, Babul J (2007). "Unfolding pathway of the dimeric and tetrameric forms of phosphofructokinase-2 from Escherichia coli." Biochemistry 46(20);6141-8. PMID: 17469854

Baez08: Baez M, Merino F, Astorga G, Babul J (2008). "Uncoupling the MgATP-induced inhibition and aggregation of Escherichia coli phosphofructokinase-2 by C-terminal mutations." FEBS Lett 582(13);1907-12. PMID: 18501195

Baez09: Baez M, Babul J (2009). "Reversible unfolding of dimeric phosphofructokinase-2 from Escherichia coli reveals a dominant role of inter-subunit contacts for stability." FEBS Lett 583(12);2054-60. PMID: 19465020

Baez11: Baez M, Wilson CA, Babul J (2011). "Folding kinetic pathway of phosphofructokinase-2 from Escherichia coli: a homodimeric enzyme with a complex domain organization." FEBS Lett 585(14);2158-64. PMID: 21627967

Baez12: Baez M, Wilson CA, Ramirez-Sarmiento CA, Guixe V, Babul J (2012). "Expanded monomeric intermediate upon cold and heat unfolding of phosphofructokinase-2 from Escherichia coli." Biophys J 103(10);2187-94. PMID: 23200052

Baez13: Baez M, Cabrera R, Pereira HM, Blanco A, Villalobos P, Ramirez-Sarmiento CA, Caniuguir A, Guixe V, Garratt RC, Babul J (2013). "A Ribokinase Family Conserved Monovalent Cation Binding Site Enhances the MgATP-induced Inhibition in E. coli Phosphofructokinase-2." Biophys J 105(1);185-93. PMID: 23823238

Benavente15: Benavente R, Esteban-Torres M, Kohring GW, Cortes-Cabrera Á, Sanchez-Murcia PA, Gago F, Acebron I, de Las Rivas B, Munoz R, Mancheno JM (2015). "Enantioselective oxidation of galactitol 1-phosphate by galactitol-1-phosphate 5-dehydrogenase from Escherichia coli." Acta Crystallogr D Biol Crystallogr 71(Pt 7);1540-54. PMID: 26143925

Bochkareva02: Bochkareva ES, Girshovich AS, Bibi E (2002). "Identification and characterization of the Escherichia coli stress protein UP12, a putative in vivo substrate of GroEL." Eur J Biochem 269(12);3032-40. PMID: 12071968

Brinkkotter00: Brinkkotter A, Kloss H, Alpert C, Lengeler JW (2000). "Pathways for the utilization of N-acetyl-galactosamine and galactosamine in Escherichia coli." Mol Microbiol 2000;37(1);125-35. PMID: 10931310

Brinkkotter02: Brinkkotter A, Shakeri-Garakani A, Lengeler JW (2002). "Two class II D-tagatose-bisphosphate aldolases from enteric bacteria." Arch Microbiol 177(5);410-9. PMID: 11976750

Cabrera02: Cabrera R, Guixe V, Alfaro J, Rodriguez PH, Babul J (2002). "Ligand-dependent structural changes and limited proteolysis of Escherichia coli phosphofructokinase-2." Arch Biochem Biophys 406(2);289-95. PMID: 12361717

Cabrera06: Cabrera R, Caniuguir A, Ambrosio AL, Guixe V, Garratt RC, Babul J (2006). "Crystallization and preliminary crystallographic analysis of the tetrameric form of phosphofructokinase-2 from Escherichia coli, a member of the ribokinase family." Acta Crystallogr Sect F Struct Biol Cryst Commun 62(Pt 9);935-7. PMID: 16946484

Cabrera08: Cabrera R, Ambrosio AL, Garratt RC, Guixe V, Babul J (2008). "Crystallographic structure of phosphofructokinase-2 from Escherichia coli in complex with two ATP molecules. Implications for substrate inhibition." J Mol Biol 383(3);588-602. PMID: 18762190

Cabrera10: Cabrera R, Babul J, Guixe V (2010). "Ribokinase family evolution and the role of conserved residues at the active site of the PfkB subfamily representative, Pfk-2 from Escherichia coli." Arch Biochem Biophys 502(1);23-30. PMID: 20599671

Cabrera11: Cabrera R, Baez M, Pereira HM, Caniuguir A, Garratt RC, Babul J (2011). "The crystal complex of phosphofructokinase-2 of Escherichia coli with fructose-6-phosphate: kinetic and structural analysis of the allosteric ATP inhibition." J Biol Chem 286(7);5774-83. PMID: 21147773

Caniuguir05: Caniuguir A, Cabrera R, Baez M, Vasquez CC, Babul J, Guixe V (2005). "Role of Cys-295 on subunit interactions and allosteric regulation of phosphofructokinase-2 from Escherichia coli." FEBS Lett 579(11);2313-8. PMID: 15848164

Daldal81: Daldal F, Fraenkel DG (1981). "Tn10 insertions in the pfkB region of Escherichia coli." J Bacteriol 147(3);935-43. PMID: 6268614

Daldal83: Daldal F (1983). "Molecular cloning of the gene for phosphofructokinase-2 of Escherichia coli and the nature of a mutation, pfkB1, causing a high level of the enzyme." J Mol Biol 1983;168(2);285-305. PMID: 6310120

Daldal84: Daldal F (1984). "Nucleotide sequence of gene pfkB encoding the minor phosphofructokinase of Escherichia coli K-12." Gene 1984;28(3);337-42. PMID: 6235149

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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