4-hydroxythreonine-4-phosphate dehydrogenase

In enzymology, 4-hydroxythreonine-4-phosphate dehydrogenase (EC 1.1.1.262) is an enzyme that catalyzes the chemical reaction

4-(phosphonooxy)-L-threonine

+ NAD⁺

 

 

 

H⁺

 

H⁺

 

(2S)-2-amino-3-oxo-4-phosphonooxybutanoic acid

+ NADH

 

4-hydroxythreonine-4-phosphate dehydrogenase
Identifiers
EC no.	1.1.1.262
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

The two substrates of this enzyme are 4-phosphonooxy-L-threonine and oxidised nicotinamide adenine dinucleotide (NAD⁺). Its products are (2S)-2-amino-3-oxo-4-phosphonooxybutanoate, reduced NADH, and a proton.^[1][2][3][4]

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 1PS6, 1PS7, 1PTM, 1R8K, 1YXO, and 2HI1.