L-ascorbate biosynthesis I (L-galactose pathway)

Linster CL, Clarke SG. l-Ascorbate biosynthesis in higher plants: the role of VTC2. Trends in Plant Science. 2008 Nov;13(11):567–73. doi: 10.1016/j.tplants.2008.08.005.; Wolucka BA, Van Montagu M. The VTC2 cycle and the de novo biosynthesis pathways for vitamin C in plants: an opinion. Phytochemistry. 2007 Nov;68(21):2602–13. doi: 10.1016/j.phytochem.2007.08.034. PMID: 17950389.; Dowdle J, Ishikawa T, Gatzek S, Rolinski S, Smirnoff N. Two genes in Arabidopsis thaliana encoding GDP-l-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability. The Plant Journal. 2007 Sep 18;52(4):673–89. doi: 10.1111/j.1365-313x.2007.03266.x.; Linster CL, Gomez TA, Christensen KC, Adler LN, Young BD, Brenner C, Clarke SG. Arabidopsis VTC2 Encodes a GDP-l-Galactose Phosphorylase, the Last Unknown Enzyme in the Smirnoff-Wheeler Pathway to Ascorbic Acid in Plants. Journal of Biological Chemistry. 2007 Jun;282(26):18879–85. doi: 10.1074/jbc.m702094200.; Laing WA, Wright MA, Cooney J, Bulley SM. The missing step of the l -galactose pathway of ascorbate biosynthesis in plants, an l -galactose guanyltransferase, increases leaf ascorbate content. Proc. Natl. Acad. Sci. U.S.A. 2007 May 29;104(22):9534–9. doi: 10.1073/pnas.0701625104.; Watanabe K, Suzuki K, Kitamura S. Characterization of a GDP-D-mannose 3'',5''-epimerase from rice. Phytochemistry. 2006 Feb;67(4):338–46. doi: 10.1016/j.phytochem.2005.12.003. PMID: 16413588.; Wolucka BA, Van Montagu M. GDP-Mannose 3',5'-Epimerase Forms GDP-L-gulose, a Putative Intermediate for the de Novo Biosynthesis of Vitamin C in Plants. Journal of Biological Chemistry. 2003 Nov;278(48):47483–90. doi: 10.1074/jbc.m309135200.; Smirnoff N, Conklin PL, Loewus FA. BIOSYNTHESIS OF ASCORBIC ACID IN PLANTS: A Renaissance. Annu. Rev. Plant. Physiol. Plant. Mol. Biol. 2001 Jun;52(1):437–67. doi: 10.1146/annurev.arplant.52.1.437.; Davey MW, Gilot C, Persiau G, Ostergaard J, Han Y, Bauw GC, Van Montagu MC. Ascorbate biosynthesis in Arabidopsis cell suspension culture. Plant Physiol. 1999 Oct;121(2):535–43. PMID: 10517845; PMCID: PMC59416.; Wheeler GL, Jones MA, Smirnoff N. The biosynthetic pathway of vitamin C in higher plants. Nature. 1998 May 28;393(6683):365–9. doi: 10.1038/30728. PMID: 9620799.

Metabolites

Diphosphate

Formula: H4P2O7 (177.9432294)

CAS ID: 2466-09-3

H+

Formula: H (1.0078246)

CAS ID: 12408-02-5

H2O

Formula: H2O (18.0105642)

CAS ID: 7732-18-5

Magnesium cation

Formula: Mg (23.98505)

CAS ID: 22537-22-0

NAD(1-)

Formula: C21H26N7O14P2 (662.1012936000001)

CAS ID: 53-84-9



Enzyme

EC Number name full name note
1.1.1.316 L-galactose 1-dehydrogenase L-galactose:NAD+ 1-oxidoreductase
1.3.2.3 L-galactonolactone dehydrogenase L-galactono-1,4-lactone:ferricytochrome-c oxidoreductase
2.7.7.13 mannose-1-phosphate guanylyltransferase GTP:alpha-D-mannose-1-phosphate guanylyltransferase
3.1.3.15 histidinol-phosphatase L-histidinol-phosphate phosphohydrolase
3.1.3.25 inositol-phosphate phosphatase myo-inositol-phosphate phosphohydrolase
3.1.3.93 L-galactose 1-phosphate phosphatase beta-L-galactose-1-phosphate phosphohydrolase
5.1.3.18 GDP-mannose 3,5-epimerase GDP-alpha-D-mannose 3,5-epimerase
5.3.1.8 mannose-6-phosphate isomerase D-mannose-6-phosphate aldose-ketose-isomerase
5.4.2.8 phosphomannomutase alpha-D-mannose 1,6-phosphomutase


Proteins

Protein ID name full name