The enzyme threonine aldolase () is an enzyme not found in humans that catalyzes the chemical reaction
L-threonine glycine + 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
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes , , , , and .
Presence in human and mouse
Some early evidence from 2005 suggests that the mouse ortholog enzyme, Tha1 (or GLY1), is synthesized and functional in mice,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 but this has not been reviewed by certain major groups like UniProt (as of August 2026).
Humans also have the remnants of the gene denoted THA1P (or GLY1), however it seems to be damaged by past mutations and inactive. RNA expression has not been found in major databases, suggesting that it isn't transcribed. Moreover, the pseudogene contains two single nucleotide deletions which would cause frameshifts even if were to be transcribed.
References