Enzymes
UniProtKB help_outline | 1,792 proteins |
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- Name help_outline GDP-α-D-glucose Identifier CHEBI:62230 Charge -2 Formula C16H23N5O16P2 InChIKeyhelp_outline MVMSCBBUIHUTGJ-LRJDVEEWSA-L SMILEShelp_outline Nc1nc2n(cnc2c(=O)[nH]1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)O[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@H]2O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 8 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 992 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline α-D-glucose 1-phosphate Identifier CHEBI:58601 (Beilstein: 3560164) help_outline Charge -2 Formula C6H11O9P InChIKeyhelp_outline HXXFSFRBOHSIMQ-VFUOTHLCSA-L SMILEShelp_outline OC[C@H]1O[C@H](OP([O-])([O-])=O)[C@H](O)[C@@H](O)[C@@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 41 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline GDP Identifier CHEBI:58189 Charge -3 Formula C10H12N5O11P2 InChIKeyhelp_outline QGWNDRXFNXRZMB-UUOKFMHZSA-K SMILEShelp_outline Nc1nc2n(cnc2c(=O)[nH]1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 184 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:30387 | RHEA:30388 | RHEA:30389 | RHEA:30390 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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A novel GDP-D-glucose phosphorylase involved in quality control of the nucleoside diphosphate sugar pool in Caenorhabditis elegans and mammals.
Adler L.N., Gomez T.A., Clarke S.G., Linster C.L.
The plant VTC2 gene encodes GDP-L-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin ... >> More
The plant VTC2 gene encodes GDP-L-galactose phosphorylase, a rate-limiting enzyme in plant vitamin C biosynthesis. Genes encoding apparent orthologs of VTC2 exist in both mammals, which produce vitamin C by a distinct metabolic pathway, and in the nematode worm Caenorhabditis elegans where vitamin C biosynthesis has not been demonstrated. We have now expressed cDNAs of the human and worm VTC2 homolog genes (C15orf58 and C10F3.4, respectively) and found that the purified proteins also display GDP-hexose phosphorylase activity. However, as opposed to the plant enzyme, the major reaction catalyzed by these enzymes is the phosphorolysis of GDP-D-glucose to GDP and D-glucose 1-phosphate. We detected activities with similar substrate specificity in worm and mouse tissue extracts. The highest expression of GDP-D-glucose phosphorylase was found in the nervous and male reproductive systems. A C. elegans C10F3.4 deletion strain was found to totally lack GDP-D-glucose phosphorylase activity; this activity was also found to be decreased in human HEK293T cells transfected with siRNAs against the human C15orf58 gene. These observations confirm the identification of the worm C10F3.4 and the human C15orf58 gene expression products as the GDP-D-glucose phosphorylases of these organisms. Significantly, we found an accumulation of GDP-D-glucose in the C10F3.4 mutant worms, suggesting that the GDP-D-glucose phosphorylase may function to remove GDP-D-glucose formed by GDP-D-mannose pyrophosphorylase, an enzyme that has previously been shown to lack specificity for its physiological D-mannose 1-phosphate substrate. We propose that such removal may prevent the misincorporation of glucosyl residues for mannosyl residues into the glycoconjugates of worms and mammals. << Less