IUBMB Enzyme Nomenclature


Accepted name: L-threonine 3-dehydrogenase

Reaction: L-threonine + NAD+ = L-2-amino-3-oxobutanoate + NADH + H+

Other name(s): L-threonine dehydrogenase; threonine 3-dehydrogenase; threonine dehydrogenase, THD

Systematic name: L-threonine:NAD+ oxidoreductase

Comments: This enzyme acts in concert with EC, glycine C-acetyltransferase, in the degradation of threonine to glycine. This threonine-degradation pathway is common to prokaryotic and eukaryotic cells and the two enzymes involved form a complex [2]. In aqueous solution, the product L-2-amino-3-oxobutanoate can spontaneously decarboxylate to form aminoacetone.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9067-99-6


1. Green, M.L. and Elliott, W.H. The enzymic formation of aminoacetone from threonine and its further metabolism. Biochem. J. 92 (1964) 537-549. [PMID: 4284408]

2. Hartshorne, D. and Greenberg, D.M. Studies on liver threonine dehydrogenase. Arch. Biochem. Biophys. 105 (1964) 173-178. [PMID: 14165492]

3. Newman, E.B., Kapoor, V. and Potter, R. Role of L-threonine dehydrogenase in the catabolism of threonine and synthesis of glycine by Escherichia coli. J. Bacteriol. 126 (1976) 1245-. [PMID: 7548]

4. Epperly, B.R. and Dekker, E.E. L-Threonine dehydrogenase from Escherichia coli. Identification of an active site cysteine residue and metal ion studies. J. Biol. Chem. 266 (1991) 6086-6092. [PMID: 2007567]

[EC created 1972]

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