MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

Arabidopsis thaliana col: L-galactose-1-phosphate phosphatase//inositol or phosphatidylinositol phosphataseInferred from experiment: VTC4
L-galactose-1-phosphate phosphataseInferred from experiment: HISN7
Escherichia coli K-12 substr. MG1655: sugar phosphatase: ybiV
sugar phosphatase: yfbT
sugar phosphatase: yidA
phosphosugar phosphatase: yigL

In Pathway: L-ascorbate biosynthesis I (L-galactose pathway)

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

Mass balance status: Balanced.

Enzyme Commission Primary Name: L-galactose 1-phosphate phosphatase

Enzyme Commission Synonyms: VTC4 (gene name) (ambiguous), IMPL2 (gene name) (ambiguous)

Standard Gibbs Free Energy (ΔrG in kcal/mol): 7.21698Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
The enzyme from plants also has the activity of EC, inositol-phosphate phosphatase. The enzymes have very low activity with D-galactose 1-phosphate (cf. EC, D-galactose 1-phosphate phosphatase).

Citations: [Laing04, Torabinejad09, Petersen10]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reaction of [phytate + H2O → a D myo-inositol penta kis phosphate + phosphate] (
i11: phytate + H2O → D-myo-inositol (1,2,4,5,6)-pentakisphosphate + phosphate (

Instance reactions of [glycerol 1-phosphate + H2O → glycerol + phosphate] (
i17: sn-glycerol 3-phosphate + H2O → glycerol + phosphate (

i18: sn-glycerol 1-phosphate + H2O → glycerol + phosphate (

Instance reactions of [a myo-inositol monophosphate + H2O → myo-inositol + phosphate] (
i1: 1D-myo-inositol 1-monophosphate + H2O → myo-inositol + phosphate (

i16: 1D-myo-inositol 3-monophosphate + H2O → myo-inositol + phosphate (

Instance reactions of [a sugar phosphate + H2O → a sugar + phosphate] (
i9: β-L-galactose 1-phosphate + H2O → L-galactopyranose + phosphate (
i10: α-D-glucopyranose 1-phosphate + H2O → D-glucopyranose + phosphate (

i19: β-D-fructofuranose 1-phosphate + H2O → β-D-fructofuranose + phosphate (3.1.3.-)

i20: α-D-galactose 1-phosphate + H2O → D-galactopyranose + phosphate (

i21: β-L-gulose 1-phosphate + H2O → L-gulopyranose + phosphate (3.1.3.-)

i23: D-glucopyranose 6-phosphate + H2O → D-glucopyranose + phosphate (

Instance reaction of [D-glucopyranose 6-phosphate + H2O → D-glucopyranose + phosphate] (
i22: α-D-glucose 6-phosphate + H2O → α-D-glucopyranose + phosphate (

Unification Links: KEGG:R07674, Rhea:26349

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


Laing04: Laing WA, Bulley S, Wright M, Cooney J, Jensen D, Barraclough D, MacRae E (2004). "A highly specific L-galactose-1-phosphate phosphatase on the path to ascorbate biosynthesis." Proc Natl Acad Sci U S A 101(48);16976-81. PMID: 15550539

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Petersen10: Petersen LN, Marineo S, Mandala S, Davids F, Sewell BT, Ingle RA (2010). "The missing link in plant histidine biosynthesis: Arabidopsis myoinositol monophosphatase-like2 encodes a functional histidinol-phosphate phosphatase." Plant Physiol 152(3);1186-96. PMID: 20023146

Torabinejad09: Torabinejad J, Donahue JL, Gunesekera BN, Allen-Daniels MJ, Gillaspy GE (2009). "VTC4 is a bifunctional enzyme that affects myoinositol and ascorbate biosynthesis in plants." Plant Physiol 150(2);951-61. PMID: 19339506

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.5 on Mon Nov 30, 2015, BIOCYC13B.