4-hydroxythreonine-4-phosphate dehydrogenase explained

4-hydroxythreonine-4-phosphate dehydrogenase
Ec Number:	1.1.1.262
Go Code:	0050570

In enzymology, a 4-hydroxythreonine-4-phosphate dehydrogenase is an enzyme that catalyzes the chemical reaction

4-phosphonooxy-L-threonine + NAD⁺

\rightleftharpoons (2S)-2-amino-3-oxo-4-phosphonooxybutanoate + NADH + H⁺

Thus, the two substrates of this enzyme are 4-phosphonooxy-L-threonine and NAD⁺, whereas its 3 products are (2S)-2-amino-3-oxo-4-phosphonooxybutanoate, 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 4-phosphonooxy-L-threonine:NAD⁺ oxidoreductase. Other names in common use include NAD⁺-dependent threonine 4-phosphate dehydrogenase, L-threonine 4-phosphate dehydrogenase, 4-(phosphohydroxy)-L-threonine dehydrogenase, PdxA, and 4-(phosphonooxy)-L-threonine:NAD⁺ oxidoreductase. This enzyme participates in vitamin B₆ metabolism.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes,,,,, and .

References

• ID . 1998 . Biosynthesis of vitamine B6: The oxidation of L-threonine 4-phosphate by PdxA . J. Am. Chem. Soc. . 120 . 8 . 1936 - 1937 . 10.1021/ja9742085 . Hsiung . Yuju . Cornish . Julie A. . Robinson . J. Kenneth . Spenser . Ian D. .
• Laber B, Maurer W, Scharf S, Stepusin K, Schmidt FS . 1999 . Vitamin B6 biosynthesis: formation of pyridoxine 5'-phosphate from 4-(phosphohydroxy)-L-threonine and 1-deoxy-D-xylulose-5-phosphate by PdxA and PdxJ protein . FEBS Lett. . 449 . 45 - 8 . 10225425 . 10.1016/S0014-5793(99)00393-2 . 1 . 33542088 . free .
• Sivaraman J, Li Y, Banks J, Cane DE, Matte A, Cygler M . 2003 . Crystal structure of Escherichia coli PdxA, an enzyme involved in the pyridoxal phosphate biosynthesis pathway . J. Biol. Chem. . 278 . 43682 - 90 . 12896974 . 10.1074/jbc.M306344200 . 44 . free .