Pathway Tools
Intro Tutorial
discounted registration ends Sept 5, 2015 (Sat)
Pathway Tools
Intro Tutorial
discounted registration ends Sept 5, 2015 (Sat)
Pathway Tools
Intro Tutorial
discounted registration ends Sept 5, 2015 (Sat)
Pathway Tools
Intro Tutorial
discounted registration ends Sept 5, 2015 (Sat)
Pathway Tools
Intro Tutorial
discounted registration ends Sept 5, 2015 (Sat)

MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number:

Enzymes and Genes:

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

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

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, 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): 7.21698 Inferred 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 [D-glucopyranose 6-phosphate + H2O → D-glucopyranose + phosphate] (
i19: α-D-glucose 6-phosphate + H2O → α-D-glucose + phosphate (

Instance reaction of [1D-myo-inositol 1,2,3,4,5,6-hexakisphosphate + H2O → a D myo-inositol penta kis phosphate + phosphate] (
i10: 1D-myo-inositol 1,2,3,4,5,6-hexakisphosphate + H2O → D-myo-inositol (1,2,4,5,6)-pentakisphosphate + phosphate (

Instance reactions of [a myo-inositol monophosphate + H2O → myo-inositol + phosphate] (
i1: 1D-myo-inositol 3-monophosphate + H2O → myo-inositol + phosphate (

i15: 1D-myo-inositol 1-monophosphate + H2O → myo-inositol + 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 sugar phosphate + H2O → a sugar + phosphate] (
i8: α-D-glucopyranose 1-phosphate + H2O → D-glucopyranose + phosphate (

i9: β-L-galactose 1-phosphate + H2O → L-galactopyranose + phosphate (
i20: β-D-glucose 6-phosphate + H2O → β-D-glucopyranose + phosphate (

i21: β-D-fructofuranose 1-phosphate + H2O → β-D-fructofuranose + phosphate (3.1.3.-)

i22: β-L-gulose 1-phosphate + H2O → L-gulopyranose + phosphate (3.1.3.-)

i23: α-D-galactose 1-phosphate + H2O → D-galactopyranose + phosphate (

i24: D-glucopyranose 6-phosphate + H2O → D-glucopyranose + phosphate (

i25: D-ribose 5-phosphate[periplasmic space] + H2O[periplasmic space]aldehydo-D-ribose[periplasmic space] + phosphate[periplasmic space] (3.1.3.-)

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 19.0 on Tue Sep 1, 2015, biocyc13.