Threonine aldolase (TA)

Threonine aldolase is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that facilitates the reversible cleavage of L-threonine into glycine and acetaldehyde (UniProt, 2023). This enzyme is a key component of amino acid metabolism in various organisms, including bacteria, fungi, and plants, where it provides an alternative pathway for glycine biosynthesis (PubMed, 2021). In humans, the gene encoding threonine aldolase (GLY1) is generally characterized as a pseudogene, meaning the enzyme lacks significant physiological activity in human tissues (NCBI, 2022). This metabolic difference makes threonine aldolase a promising target for antimicrobial and antifungal drug discovery, as inhibitors could selectively disrupt pathogen metabolism without affecting the host (Journal of Biological Chemistry, 2019). Research has identified its importance in the growth and virulence of pathogens such as Mycobacterium tuberculosis and Toxoplasma gondii (PubMed, 2020). Potential therapeutic agents targeting this enzyme include substrate analogs and PLP-antagonists, which aim to block the active site and halt glycine production (PubChem, 2023). Despite its potential, most inhibitors are currently in the preclinical stage, and challenges remain regarding the specificity of these compounds against other PLP-dependent enzymes (ScienceDirect, 2022). The enzyme's structure and mechanism are well-studied, providing a solid foundation for structure-based drug design (Nature Communications, 2018).

Other names

L-threonine aldolaseL-allo-threonine aldolaseGlycine-forming threonine aldolaseL-threonine acetaldehyde-lyase

The enzyme utilizes a pyridoxal-5'-phosphate (PLP) cofactor to catalyze the reversible retro-aldol cleavage of L-threonine or L-allo-threonine, yielding glycine and acetaldehyde.