KEGG   ENZYME: 1.3.2.3Help
Entry
EC 1.3.2.3                  Enzyme                                 

Name
L-galactonolactone dehydrogenase;
galactonolactone dehydrogenase;
L-galactono-gamma-lactone dehydrogenase;
L-galactono-gamma-lactone:ferricytochrome-c oxidoreductase;
GLDHase;
GLDase
Class
Oxidoreductases;
Acting on the CH-CH group of donors;
With a cytochrome as acceptor
BRITE hierarchy
Sysname
L-galactono-1,4-lactone:ferricytochrome-c oxidoreductase
Reaction(IUBMB)
L-galactono-1,4-lactone + 4 ferricytochrome c = L-dehydroascorbate + 4 ferrocytochrome c + 4 H+ (overall reaction) [RN:R00640];
(1a) L-galactono-1,4-lactone + 2 ferricytochrome c = L-ascorbate + 2 ferrocytochrome c + 2 H+ [RN:R07679];
(1b) L-ascorbate + 2 ferricytochrome c = L-dehydroascorbate + 2 ferrocytochrome c + 2 H+ (spontaneous)
Reaction(KEGG)
Substrate
L-galactono-1,4-lactone [CPD:C01115];
ferricytochrome c [CPD:C00125];
L-ascorbate [CPD:C00072]
Product
L-dehydroascorbate [CPD:C05422];
ferrocytochrome c [CPD:C00126];
H+ [CPD:C00080];
L-ascorbate [CPD:C00072]
Comment
This enzyme catalyses the final step in the biosynthesis of L-ascorbic acid in higher plants and in nearly all higher animals with the exception of primates and some birds [5]. The enzyme is very specific for its substrate L-galactono-1,4-lactone as D-galactono-gamma-lactone, D-gulono-gamma-lactone, L-gulono-gamma-lactone, D-erythronic-gamma-lactone, D-xylonic-gamma-lactone, L-mannono-gamma-lactone, D-galactonate, D-glucuronate and D-gluconate are not substrates [5]. FAD, NAD+, NADP+ and O2 (cf. EC 1.3.3.12, L-galactonolactone oxidase) cannot act as electron acceptor [5].
History
EC 1.3.2.3 created 1961, modified 2006
Pathway
Ascorbate and aldarate metabolism
Metabolic pathways
Biosynthesis of secondary metabolites
Orthology
K00225  
L-galactono-1,4-lactone dehydrogenase
Genes
ATH: 
AT3G47930(GLDH)
ALY: 
CRB: 
EUS: 
BRP: 
103873188(GLDH)
BNA: 
THJ: 
CIT: 
CIC: 
TCC: 
GRA: 
EGR: 
GMX: 
PVU: 
VRA: 
MTR: 
CAM: 
ADU: 
AIP: 
FVE: 
PPER: 
PMUM: 
MDM: 
PXB: 
CSV: 
CMO: 
RCU: 
JCU: 
POP: 
POPTR_0006s04170g(POPTRDRAFT_762038) POPTR_0016s03990g(POPTRDRAFT_1102986)
VVI: 
SLY: 
544206(gldh)
SPEN: 
SOT: 
102577860(GLDH)
SIND: 
BVG: 
NNU: 
OSA: 
DOSA: 
Os11t0143500-01(Os11g0143500) Os12t0139600-01(Os12g0139600)
OBR: 
BDI: 
SBI: 
SORBI_05g002615(SORBIDRAFT_05g002615)
ZMA: 
SITA: 
PDA: 
EGU: 
MUS: 
ATR: 
SMO: 
PPP: 
CRE: 
VCN: 
OLU: 
OTA: 
BPG: 
MIS: 
MPP: 
CSL: 
CVR: 
APRO: 
CME: 
CCP: 
MBR: 
SRE: 
PTI: 
TPS: 
AAF: 
NGD: 
PIF: 
PSOJ: 
SPAR: 
EHX: 
GTT: 
 » show all
Taxonomy
Reference
1
  Authors
Mapson, L.W. and Breslow, E.
  Title
Properties of partially purified L-galactono-gamma-lactone dehydrogenase.
  Journal
Biochem. J. 65 (1957) 29.
Reference
2  [PMID:13126087]
  Authors
MAPSON LW, ISHERWOOD FA, CHEN YT.
  Title
Biological synthesis of L-ascorbic acid: the conversion of L-galactono-gamma-lactone into L-ascorbic acid by plant mitochondria.
  Journal
Biochem. J. 56 (1954) 21-8.
Reference
3  [PMID:13126085]
  Authors
ISHERWOOD FA, CHEN YT, MAPSON LW.
  Title
Synthesis of L-ascorbic acid in plants and animals.
  Journal
Biochem. J. 56 (1954) 1-15.
Reference
4  [PMID:7775377]
  Authors
Oba K, Ishikawa S, Nishikawa M, Mizuno H, Yamamoto T.
  Title
Purification and properties of L-galactono-gamma-lactone dehydrogenase, a key enzyme for ascorbic acid biosynthesis, from sweet potato roots.
  Journal
J. Biochem. (Tokyo). 117 (1995) 120-4.
Reference
5  [PMID:9374475]
  Authors
Ostergaard J, Persiau G, Davey MW, Bauw G, Van Montagu M.
  Title
Isolation of a cDNA coding for L-galactono-gamma-lactone dehydrogenase, an enzyme involved in the biosynthesis of ascorbic acid in plants. Purification, characterization, cDNA cloning, and expression in yeast.
  Journal
J. Biol. Chem. 272 (1997) 30009-16.
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
9029-02-1

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