InterPro domain: IPR014027

The UDP-glucose/GDP-mannose dehydrogenases are a small group of enzymes which possesses the ability to catalyse the NAD-dependent 2-fold oxidation of an alcohol to an acid without the release of an aldehyde intermediate [ 1 , 2 ].

The enzymes have a wide range of functions. In plants UDP-glucose dehydrogenase, 1.1.1.22 , is an important enzyme in the synthesis of hemicellulose and pectin [ 3 ], which are the components of newly formed cell walls; while in zebrafish UDP-glucose dehydrogenase is required for cardiac valve formation [ 4 ]. In Xanthomonas campestris, a plant pathogen, UDP-glucose dehydrogenase is required for virulence [ 5 ].

GDP-mannose dehydrogenase, 1.1.1.132 , catalyses the formation of GDP-mannuronic acid, which is the monomeric unit from which the exopolysaccharide alginate is formed. Alginate is secreted by a number of bacteria, which include Pseudomonas aeruginosa and Azotobacter vinelandii. In P. aeruginosa, alginate is believed to play an important role in the bacteria's resistance to antibiotics and the host immune response [ 6 ], while in A. vinelandii it is essential for the encystment process [ 7 ].

This entry represents the C-terminal substrate-binding domain of these enzymes. Structural studies indicate that this domain forms an incomplete dinucleotide binding fold [ 8 , 9 ].

1. Purification and characterization of guanosine diphospho-D-mannose dehydrogenase. A key enzyme in the biosynthesis of alginate by Pseudomonas aeruginosa. J. Biol. Chem. 264, 9380-5
2. Properties and kinetic analysis of UDP-glucose dehydrogenase from group A streptococci. Irreversible inhibition by UDP-chloroacetol. J. Biol. Chem. 272, 3416-22
3. Molecular cloning and characterization of a cDNA encoding poplar UDP-glucose dehydrogenase, a key gene of hemicellulose/pectin formation. Biochim. Biophys. Acta 1576, 53-8
4. UDP-glucose dehydrogenase required for cardiac valve formation in zebrafish. Science 293, 1670-3
5. UDP-glucose dehydrogenase gene of Xanthomonas campestris is required for virulence. Biochem. Biophys. Res. Commun. 287, 550-5
6. Allosterism and cooperativity in Pseudomonas aeruginosa GDP-mannose dehydrogenase. Biochemistry 41, 9637-45
7. The Azotobacter vinelandii response regulator AlgR is essential for cyst formation. J. Bacteriol. 181, 141-8
8. The first structure of UDP-glucose dehydrogenase reveals the catalytic residues necessary for the two-fold oxidation. Biochemistry 39, 7012-23
9. Crystal structure of GDP-mannose dehydrogenase: a key enzyme of alginate biosynthesis in P. aeruginosa. Biochemistry 42, 4658-68