Escherichia coli K-12 substr. MG1655 Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:,

Enzymes and Genes:
low-specificity L-threonine aldolaseInferred from experiment: ltaE
serine hydroxymethyltransferase: glyA

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.

Mass balance status: Balanced.

Direct generic reaction:
DL-allothreonine ↔ acetaldehyde + glycine (4.1.2.-)

Enzyme Commission Primary Name for low-specificity L-threonine aldolase

Enzyme Commission Synonyms for LtaE

Enzyme Commission Primary Name for L-allo-threonine aldolase

Enzyme Commission Summary for
Requires pyridoxal phosphate. The low-specificity L-threonine aldolase can act on both L-threonine and L-allo-threonine [Yamada70, Kumagai72]. The enzyme from Escherichia coli can also act on L-threo-phenylserine and L-erythro-phenylserine [Liu98]. The enzyme can also catalyse the aldol condensation of glycolaldehyde and glycine to form 4-hydroxy-L-threonine, an intermediate of pyridoxal phosphate biosynthesis [Liu97]. Different from EC, L-threonine aldolase, and EC, L-allo-threonine aldolase.

Enzyme Commission Summary for
Requires pyridoxal phosphate. This enzyme, characterized from the bacterium Aeromonas jandaei, is specific for L-allo-threonine and can not act on either L-threonine or L-serine. Different from EC, L-threonine aldolase, and EC, low-specificity L-threonine aldolase. A previously listed enzyme with this name, EC, was deleted in 1971 after it was found to be identical to EC, glycine hydroxymethyltransferase.

Citations: [Kim10b, Kataoka97a]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reaction of [DL-allothreonine ↔ acetaldehyde + glycine] (4.1.2.-):
i1: L-allo-threonine ↔ glycine + acetaldehyde (

Relationship Links: BRENDA:EC:, BRENDA:EC:, ENZYME:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:, IUBMB-ExplorEnz:EC:


Kataoka97a: 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

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

Kumagai72: Kumagai H, Nagate T, Yoshida H, Yamada H (1972). "Threonine aldolase from Candida humicola. II. Purification, crystallization and properties." Biochim Biophys Acta 258(3);779-90. PMID: 5017702

Liu97: 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

Liu98: 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

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

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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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