MetaCyc

Parent Class:

EC-Numbers → 4 -- Lyases → 4.2 -- Carbon-oxygen lyases → 4.2.1 -- Hydro-lyases

Synonyms: guanosine 5′-diphosphate-D-mannose oxidoreductase, guanosine diphosphomannose oxidoreductase, guanosine diphosphomannose 4,6-dehydratase, GDP-D-mannose dehydratase, GDP-D-mannose 4,6-dehydratase, Gmd, GDP-mannose 4,6-hydro-lyase, GDP-mannose 4,6-hydro-lyase (GDP-4-dehydro-6-deoxy-D-mannose-forming)

Systematic Name: GDP-α-D-mannose 4,6-hydro-lyase (GDP-4-dehydro-α-D-rhamnose-forming)

Unification Links: BRENDA:4.2.1.47, ENZYME:4.2.1.47, IUBMB-ExplorEnz:4.2.1.47

Reaction:
GDP-α-D-mannose → GDP-4-dehydro-α-D-rhamnose + H₂O

Enzymes and Genes:
GDP-mannose 4,6-dehydratase: gmd ( Escherichia coli K-12 substr. MG1655 )
GDP-mannose 4,6-dehydratase: gmd ( Brucella abortus 2308 )
GDP-mannose 4,6-dehydratase: fscMIII ( Streptomyces sp. FR-008 )
GDP-D-mannose 4,6-dehydratase: rfbD ( Vibrio cholerae O1 )
GDP-α-D-mannose 4,6-dehydratase: gmd ( Aggregatibacter actinomycetemcomitans )
GDP-D-mannose dehydratase: gmd ( Aneurinibacillus thermoaerophilus L420-91 )
GDP-D-mannose 4,6-dehydratase: gmd ( Pseudomonas aeruginosa )
GDP-mannose 4,6-dehydratase: MUR1 ( Arabidopsis thaliana col )
GDP-mannose 4,6-dehydratase: gmd ( Escherichia coli O157:H7 )

Summary:
The bacterial enzyme requires bound NAD⁺. This enzyme forms the first step in the biosynthesis of GDP-D-rhamnose and GDP-L-fucose. In Aneurinibacillus thermoaerophilus L420-91^T, this enzyme acts as a bifunctional enzyme, catalysing the above reaction as well as the reaction catalysed by EC 1.1.1.281, GDP-4-dehydro-6-deoxy-D-mannose reductase [Kneidinger01]. Belongs to the short-chain dehydrogenase/reductase enzyme family, having homologous structures and a conserved catalytic triad of Lys, Tyr and Ser/Thr residues [Mulichak02].