Threonine aldolase

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threonine aldolase
L-Threonine aldolase homotetramer, Thermotoga maritima
EC no.
CAS no.62213-23-4
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
threonine aldolase 1 pseudogene
NCBI gene390816
Other data
LocusChr. 17 q25.3

In enzymology, a threonine aldolase (EC is an enzyme that catalyzes the chemical reaction

L-threonine glycine + acetaldehyde

Hence, this enzyme has one substrate, L-threonine, and two products, glycine and acetaldehyde.

This enzyme belongs to the family of lyases, specifically the aldehyde-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is L-threonine acetaldehyde-lyase (glycine-forming). This enzyme is also called L-threonine acetaldehyde-lyase. This enzyme participates in glycine, serine and threonine metabolism. It employs one cofactor, pyridoxal phosphate.

Structural studies[edit]

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1JG8, 1LW4, 1LW5, 1M6S, and 1SVV.

Presence in human and mouse[edit]

The enzyme is synthesized and functional in mice.[1]

Humans also have the remnants of the gene, coding this enzyme (GLY1), however it is damaged by past mutations and inactive.[1] Human gene contains two single nucleotide deletions causing frameshifts and premature stop codons. Also, the encoded protein would not be active anyway due mutations in other highly conserved regions. Human gene is no longer transcribed into RNA.


  1. ^ a b Alasdair J Edgar (2005) Mice have a transcribed L-threonine aldolase/GLY1 gene, but the human GLY1 gene is a non-processed pseudogene. BMC Genomics March 2005, 6:32. pdf
  • Bell SC; Turner JM (1973). "Bacterial threonine aldolase and serine hydroxymethyltransferase enzyme". Biochem. Soc. Trans. 1 (3): 678–681. doi:10.1042/bst0010678.
  • KARASEK MA, GREENBERG DM (1957). "Studies on the properties of threonine aldolases". J. Biol. Chem. 227 (1): 191–205. PMID 13449064.
  • 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. doi:10.1016/0005-2744(72)90179-9. PMID 5017702.