IUBMB Enzyme Nomenclature


Accepted name: D-galacturonate reductase

Reaction: L-galactonate + NADP+ = D-galacturonate + NADPH + H+

Other name(s): GalUR; gar1 (gene name)

Systematic name: L-galactonate:NADP+ oxidoreductase

Comments: The enzyme from plants is involved in ascorbic acid (vitamin C) biosynthesis [1,2]. The enzyme from the fungus Trichoderma reesei (Hypocrea jecorina) is involved in a eukaryotic degradation pathway of D-galacturonate. It is also active with D-glucuronate and glyceraldehyde [3]. Neither enzyme shows any activity with NADH.

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


1. Isherwood, F.A. and Mapson, L.W. Biological synthesis of ascorbic acid: the conversion of derivatives of D-galacturonic acid into L-ascorbic acid by plant extracts. Biochem. J. 64 (1956) 13-22. [PMID: 13363799]

2. Agius, F., Gonzalez-Lamothe, R., Caballero, J.L., Munoz-Blanco, J., Botella, M.A. and Valpuesta, V. Engineering increased vitamin C levels in plants by overexpression of a D-galacturonic acid reductase. Nat. Biotechnol. 21 (2003) 177-181. [PMID: 12524550]

3. Kuorelahti, S., Kalkkinen, N., Penttila, M., Londesborough, J. and Richard, P. Identification in the mold Hypocrea jecorina of the first fungal D-galacturonic acid reductase. Biochemistry 44 (2005) 11234-11240. [PMID: 16101307]

4. Martens-Uzunova, E.S. and Schaap, P.J. An evolutionary conserved D-galacturonic acid metabolic pathway operates across filamentous fungi capable of pectin degradation. Fungal Genet. Biol. 45 (2008) 1449-1457. [PMID: 18768163]

[EC created 2013]

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