IUBMB Enzyme Nomenclature


Accepted name: NAD(P)H-hydrate epimerase

Reaction: (1) (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide
(2) (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = (6S)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate

Glossary: 6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = NADHX = NADH-hydrate
6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = NADPHX = NADPH-hydrate

Other name(s): NAD(P)HX epimerase

Systematic name: (6R)-6β-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide 6-epimerase

Comments: The enzyme can use either (R)-NADH-hydrate or (R)-NADPH-hydrate as a substrate. Its physiological role is to convert the (R) forms to the (S) forms, which could then be restored to active dinucleotides by EC, ATP-dependent NAD(P)H-hydrate dehydratase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Marbaix, A.Y., Noel, G., Detroux, A.M., Vertommen, D., Van Schaftingen, E. and Linster, C.L. Extremely conserved ATP- or ADP-dependent enzymatic system for nicotinamide nucleotide repair. J. Biol. Chem. 286 (2011) 41246-41252. [PMID: 21994945]

[EC created 2012]

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