PROSITE documentation PDOC00061
Aldo/keto reductase family signatures


The aldo-keto reductase family [1,2] groups together a number of structurally and functionally related NADPH-dependent oxidoreductases as well as some other proteins. The proteins known to belong to this family are:

  • Aldehyde reductase (EC
  • Aldose reductase (EC
  • 3-α-hydroxysteroid dehydrogenase (EC, which terminates androgen action by converting 5-α-dihydrotestosterone to 3-α- androstanediol.
  • Prostaglandin F synthase (EC which catalyzes the reduction of prostaglandins H2 and D2 to F2-α.
  • D-sorbitol-6-phosphate dehydrogenase (EC from apple.
  • Morphine 6-dehydrogenase (EC from Pseudomonas putida plasmid pMDH7.2 (gene morA).
  • Chlordecone reductase (EC which reduces the pesticide chlordecone (kepone) to the corresponding alcohol.
  • 2,5-diketo-D-gluconic acid reductase (EC which catalyzes the reduction of 2,5-diketogluconic acid to 2-keto-L-gulonic acid, a key intermediate in the production of ascorbic acid.
  • NAD(P)H-dependent xylose reductase (EC 1.1.1.-) from the yeast Pichia stipitis. This enzyme reduces xylose into xylit.
  • Trans-1,2-dihydrobenzene-1,2-diol dehydrogenase (EC
  • 3-oxo-5-β-steroid 4-dehydrogenase (EC which catalyzes the reduction of delta(4)-3-oxosteroids.
  • A soybean reductase, which co-acts with chalcone synthase in the formation of 4,2',4'-trihydroxychalcone.
  • Frog eye lens rho crystallin.
  • Yeast GCY protein, whose function is not known.
  • Leishmania major P110/11E protein. P110/11E is a developmentally regulated protein whose abundance is markedly elevated in promastigotes compared with amastigotes. Its exact function is not yet known.
  • Escherichia coli hypothetical protein yafB.
  • Escherichia coli hypothetical protein yghE.
  • Yeast hypothetical protein YBR149w.
  • Yeast hypothetical protein YHR104w.
  • Yeast hypothetical protein YJR096w.

These proteins have all about 300 amino acid residues. We derived 3 consensus patterns specific to this family of proteins. The first one is located in the N-terminal section of these proteins. The second pattern is located in the central section. The third pattern, located in the C-terminal, is centered on a lysine residue whose chemical modification, in aldose and aldehyde reductases, affect the catalytic efficiency.

Last update:

April 2006 / Patterns revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

ALDOKETO_REDUCTASE_1, PS00798; Aldo/keto reductase family signature 1  (PATTERN)

ALDOKETO_REDUCTASE_2, PS00062; Aldo/keto reductase family signature 2  (PATTERN)

ALDOKETO_REDUCTASE_3, PS00063; Aldo/keto reductase family putative active site signature  (PATTERN)


1AuthorsBohren K.M. Bullock B. Wermuth B. Gabbay K.H.
TitleThe aldo-keto reductase superfamily. cDNAs and deduced amino acid sequences of human aldehyde and aldose reductases.
SourceJ. Biol. Chem. 264:9547-9551(1989).
PubMed ID2498333

2AuthorsBruce N.C. Willey D.L. Coulson A.F.M. Jeffery J.
TitleBacterial morphine dehydrogenase further defines a distinct superfamily of oxidoreductases with diverse functional activities.
SourceBiochem. J. 299:805-811(1994).
PubMed ID8192670

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