GDP-L-galactose phosphorylase
| GDP-L-galactose phosphorylase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.7.7.69 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
GDP-L-galactose phosphorylase (EC 2.7.7.69, VTC2, VTC5) is an enzyme with systematic name GDP:alpha-L-galactose 1-phosphate guanylyltransferase.[1] It catalyses two related chemical reactions involving α-D-mannose 1-phosphate. In the first, this compound reacts with guanosine diphosphate galactose (GDP-β-L-galactose) to give guanosine diphosphate mannose and β-L-galactose 1-phosphate. This is an important enzyme in the Smirnoff-Wheeler pathway that allows plants to make ascorbic acid.[2][3][4][5]
The plant enzyme can also use α-D-mannose 1-phosphate and GDP-α-D-glucose to yield guanosine diphosphate mannose and glucose 1-phosphate:[2]
This reaction is also found in the nematode Caenorhabditis elegans and in mammals, using the same protein.[6]
References
- ↑ Enzyme 2.7.7.69 at KEGG Pathway Database.
- 1 2 Linster CL, Gomez TA, Christensen KC, Adler LN, Young BD, Brenner C, Clarke SG (June 2007). "Arabidopsis VTC2 encodes a GDP-L-galactose phosphorylase, the last unknown enzyme in the Smirnoff-Wheeler pathway to ascorbic acid in plants". The Journal of Biological Chemistry. 282 (26): 18879–85. doi:10.1074/jbc.m702094200. PMC 2556065. PMID 17462988.
- ↑ Linster CL, Adler LN, Webb K, Christensen KC, Brenner C, Clarke SG (July 2008). "A second GDP-L-galactose phosphorylase in arabidopsis en route to vitamin C. Covalent intermediate and substrate requirements for the conserved reaction". The Journal of Biological Chemistry. 283 (27): 18483–92. doi:10.1074/jbc.m802594200. PMC 2441562. PMID 18463094.
- ↑ Dowdle J, Ishikawa T, Gatzek S, Rolinski S, Smirnoff N (November 2007). "Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability". The Plant Journal. 52 (4): 673–89. doi:10.1111/j.1365-313x.2007.03266.x. PMID 17877701.
- ↑ Müller-Moulé P (September 2008). "An expression analysis of the ascorbate biosynthesis enzyme VTC2". Plant Molecular Biology. 68 (1–2): 31–41. Bibcode:2008PMolB..68...31M. doi:10.1007/s11103-008-9350-4. PMID 18516687. S2CID 34035343.
- ↑ Adler, Lital N.; Gomez, Tara A.; Clarke, Steven G.; Linster, Carole L. (2011). "A Novel GDP-d-glucose Phosphorylase Involved in Quality Control of the Nucleoside Diphosphate Sugar Pool in Caenorhabditis elegans and Mammals". Journal of Biological Chemistry. 286 (24): 21511–21523. doi:10.1074/jbc.M111.238774. PMC 3122210. PMID 21507950.
External links
- GDP-L-galactose+phosphorylase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)