Oxidoreductases;
Acting on the CH-OH group of donors;
With NAD+ or NADP+ as acceptor
BRITE hierarchy

uronate:NAD+ 1-oxidoreductase

(1) beta-D-galacturonate + NAD+ = D-galactaro-1,5-lactone + NADH + H+ [RN:R10841];
(2) beta-D-glucuronate + NAD+ = D-glucaro-1,5-lactone + NADH + H+ [RN:R10842]

R10841 R10842
Reaction

beta-D-galacturonate;
NAD+ [CPD:C00003];
beta-D-glucuronate

Requires Mg2+. The enzyme, characterized from the bacterium Agrobacterium fabrum, participates in oxidative degradation pathways for galacturonate and glucuronate. The enzyme can only accept the beta anomeric form of the substrate [4]. The 1,5-lactone product is rather stable at cytosolic pH and does not hydrolyse spontaneously at a substantial rate.

EC 1.1.1.203 created 1972 as EC 1.2.1.35, transferred 1984 to EC 1.1.1.203, modified 2014

1  [PMID:13657147]

KILGORE WW, STARR MP.

Uronate oxidation by phytopathogenic pseudomonads.

Nature 183:1412-3 (1959)
DOI:10.1038/1831412a0

2  [PMID:19921179]

Boer H, Maaheimo H, Koivula A, Penttila M, Richard P

Identification in Agrobacterium tumefaciens of the D-galacturonic acid dehydrogenase gene.

Appl Microbiol Biotechnol 86:901-9 (2010)
DOI:10.1007/s00253-009-2333-9

[atu:Atu3143]

3  [PMID:22493433]

Andberg M, Maaheimo H, Boer H, Penttila M, Koivula A, Richard P

Characterization of a novel Agrobacterium tumefaciens galactarolactone cycloisomerase enzyme for direct conversion of D-galactarolactone to 3-deoxy-2-keto-L-threo-hexarate.

J Biol Chem 287:17662-71 (2012)
DOI:10.1074/jbc.M111.335240

4  [PMID:21676870]

Parkkinen T, Boer H, Janis J, Andberg M, Penttila M, Koivula A, Rouvinen J

Crystal structure of uronate dehydrogenase from Agrobacterium tumefaciens.

J Biol Chem 286:27294-300 (2011)
DOI:10.1074/jbc.M111.254854