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MetaCyc Pathway: glycine biosynthesis IV
Inferred from experiment

Pathway diagram: glycine biosynthesis IV

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: BiosynthesisAmino Acids BiosynthesisProteinogenic Amino Acids BiosynthesisGlycine Biosynthesis

Some taxa known to possess this pathway include : Saccharomyces cerevisiae

Expected Taxonomic Range: Fungi

General Background

Saccharomyces cerevisiae can biosynthesize glycine via three different pathways. When the cells are grown with glucose as the carbon source, two alternative pathways operate. In one pathway L-threonine aldolase, encoded by GLY1, produces glycine from L-threonine (which is produced from the glycolytic intermediate oxaloacetate) (see glycine biosynthesis IV). In the other pathway glycine is formed from L-serine (a product of 3-phospho-D-glycerate, another glycolytic intermediate) via two serine hydroxymethyltransferases - a cytosolic enzyme (SHMT2) and a mitochondrial enzyme (SHMT1) (see glycine biosynthesis I). The two isoforms are reported to work in opposite directions, depending on the culture conditions [Kastanos97].

When the cells are grown with a non-fermentable carbon source, such as ethanol and acetate, glycine is produced from glyoxylate, a product of the glyoxylate cycle, by the enzyme alanine--glyoxylate aminotransferase 1 (see glycine biosynthesis III).

About This Pathway

It has been recognized since 1969 that many organisms possess an L-threonine aldolase that catalyzes the interconversion of L-threonine and glycine [Morris69]. The enzyme is widespread in nature and has been shown to exist in both eukaryotes and prokaryotes [Yamada70, Liu97a, Kataoka97, Kataoka97a, Liu98a, Liu98b, Joshi06]. In yeast the enzyme is important for the synthesis of cellular glycine [Monschau97]. In bacteria, despite the enzyme's wide distribution, its physiological significance is not certain.

Variants: glycine biosynthesis I, glycine biosynthesis II, glycine biosynthesis III

Created 27-Feb-2004 by Hong E, Saccharomyces Genome Database
Revised 23-Aug-2007 by Krieger CJ, Saccharomyces Genome Database
Revised 07-Jan-2008 by Caspi R, SRI International


Joshi06: Joshi V, Laubengayer KM, Schauer N, Fernie AR, Jander G (2006). "Two Arabidopsis threonine aldolases are nonredundant and compete with threonine deaminase for a common substrate pool." Plant Cell 18(12);3564-75. PMID: 17172352

Kastanos97: Kastanos EK, Woldman YY, Appling DR (1997). "Role of mitochondrial and cytoplasmic serine hydroxymethyltransferase isozymes in de novo purine synthesis in Saccharomyces cerevisiae." Biochemistry 36(48);14956-64. PMID: 9398220

Kataoka97: Kataoka M, Wada M, Nishi K, Yamada H, Shimizu S (1997). "Purification and characterization of L-allo-threonine aldolase from Aeromonas jandaei DK-39." FEMS Microbiol Lett 151(2);245-8. PMID: 9228760

Kataoka97a: Kataoka M, Ikemi M, Morikawa T, Miyoshi T, Nishi K, Wada M, Yamada H, Shimizu S (1997). "Isolation and characterization of D-threonine aldolase, a pyridoxal-5'-phosphate-dependent enzyme from Arthrobacter sp. DK-38." Eur J Biochem 248(2);385-93. PMID: 9346293

Liu97a: Liu JQ, Nagata S, Dairi T, Misono H, Shimizu S, Yamada H (1997). "The GLY1 gene of Saccharomyces cerevisiae encodes a low-specific L-threonine aldolase that catalyzes cleavage of L-allo-threonine and L-threonine to glycine--expression of the gene in Escherichia coli and purification and characterization of the enzyme." Eur J Biochem 245(2);289-93. PMID: 9151955

Liu98a: Liu JQ, Ito S, Dairi T, Itoh N, Kataoka M, Shimizu S, Yamada H (1998). "Gene cloning, nucleotide sequencing, and purification and characterization of the low-specificity L-threonine aldolase from Pseudomonas sp. strain NCIMB 10558." Appl Environ Microbiol 64(2);549-54. PMID: 9464392

Liu98b: Liu JQ, Dairi T, Itoh N, Kataoka M, Shimizu S, Yamada H (1998). "Gene cloning, biochemical characterization and physiological role of a thermostable low-specificity L-threonine aldolase from Escherichia coli." Eur J Biochem 1998;255(1);220-6. PMID: 9692922

Monschau97: Monschau N, Stahmann KP, Sahm H, McNeil JB, Bognar AL (1997). "Identification of Saccharomyces cerevisiae GLY1 as a threonine aldolase: a key enzyme in glycine biosynthesis." FEMS Microbiol Lett 150(1);55-60. PMID: 9163906

Morris69: Morris JG (1969). "Utilization of L-threnonine by a pseudomonad: a catabolic role for L-threonine aldolase." Biochem J 115(3);603-5. PMID: 5353532

Yamada70: Yamada H, Kumagai H, Nagate T, Yoshida H (1970). "Crystalline threonine aldolase from Candida humicola." Biochem Biophys Res Commun 39(1);53-8. PMID: 5438301

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

Contestabile01: Contestabile R, Paiardini A, Pascarella S, di Salvo ML, D'Aguanno S, Bossa F (2001). "l-Threonine aldolase, serine hydroxymethyltransferase and fungal alanine racemase. A subgroup of strictly related enzymes specialized for different functions." Eur J Biochem 268(24);6508-25. PMID: 11737206

Kim10b: Kim J, Kershner JP, Novikov Y, Shoemaker RK, Copley SD (2010). "Three serendipitous pathways in E. coli can bypass a block in pyridoxal-5'-phosphate synthesis." Mol Syst Biol 6;436. PMID: 21119630

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Wed May 4, 2016, biocyc13.