CATH Classification

Domain Context

CATH Clusters

Superfamily 3.40.1190.20
Functional Family Bifunctional NAD(P)H-hydrate repair enzyme Nnr

Enzyme Information
NAD(P)H-hydrate epimerase.
based on mapping to UniProt Q9X024
(1) (6R)-6-beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide = (6S)-6-beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide. (2) (6R)-6-beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate = (6S)-6-beta-hydroxy-1,4,5,6- tetrahydronicotinamide-adenine dinucleotide phosphate.
-!- 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
ADP-dependent NAD(P)H-hydrate dehydratase.
based on mapping to UniProt Q9X024
(1) ADP + (6S)-6-beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine- dinucleotide = AMP + phosphate + NADH. (2) ADP + (6S)-6-beta-hydroxy-1,4,5,6-tetrahydronicotinamide adenine- dinucleotide phosphate = AMP + phosphate + NADPH.
-!- Acts equally well on hydrated NADH and hydrated NADPH. -!- NAD(P)H spontaneously hydrates to both the (6S)- and (6R)- isomers. -!- The enzyme from bacteria consists of two domains, one of which acts as an NAD(P)H-hydrate epimerase that interconverts the two isomers to a 60:40 ratio (cf. EC, while the other catalyzes the dehydration. -!- Hence the enzyme can restore the complete mixture of isomers into NAD(P)H. -!- The enzyme has no activity with ATP, contrary to the enzyme from eukaryotes (cf. EC

UniProtKB Entries (1)

Thermotoga maritima MSB8
Bifunctional NAD(P)H-hydrate repair enzyme Nnr

PDB Structure

External Links
Organism Escherichia
Primary Citation
Identification of unknown protein function using metabolite cocktail screening.
Shumilin, I.A., Cymborowski, M., Chertihin, O., Jha, K.N., Herr, J.C., Lesley, S.A., Joachimiak, A., Minor, W.