Lupinus

In enzymology, a L-threonine 3-dehydrogenase (EC 1.1.1.103) is an enzyme that catalyzes the chemical reaction

L-threonine + NAD⁺ L-2-amino-3-oxobutanoate + NADH + H⁺

Thus, the two substrates of this enzyme are L-threonine and NAD⁺, whereas its 3 products are L-2-amino-3-oxobutanoate, NADH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is L-threonine:NAD⁺ oxidoreductase. Other names in common use include L-threonine dehydrogenase, threonine 3-dehydrogenase, and threonine dehydrogenase. This enzyme participates in glycine, serine and threonine metabolism.

Structural studies

As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 2D8A, 2DFV, and 2DQ4.

References

• Green ML, Elliott WH (1964). "The enzymic formation of aminoacetone from threonine and its further metabolism". Biochem. J. 92 (3): 537–49. doi:10.1042/bj0920537. PMC 1206098. PMID 4284408.
• Hartshorne D, Greenberg DM (1964). "Studies on liver threonine dehydrogenase". Arch. Biochem. Biophys. 105: 173–8. doi:10.1016/0003-9861(64)90250-4. PMID 14165492.
• Epperly BR, Dekker EE (April 1991). "L-threonine dehydrogenase from Escherichia coli. Identification of an active site cysteine residue and metal ion studies". The Journal of Biological Chemistry. 266 (10): 6086–92. doi:10.1016/S0021-9258(18)38087-6. PMID 2007567.
• Edgar AJ (October 2002). "The human L-threonine 3-dehydrogenase gene is an expressed pseudogene". BMC Genetics. 3: 18. doi:10.1186/1471-2156-3-18. PMC 131051. PMID 12361482.