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MetaCyc Reaction:

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

EC Number:

Enzymes and Genes:

Arabidopsis thaliana: 4-hydroxybenzoate polyprenyltransferase: PPT1
Arabidopsis thaliana col: 4-hydroxybenzoate polyprenyl diphosphate transferaseInferred from experiment: AT4G23660
Pseudomonas putida: 4-hydroxybenzoate-polyprenyltransferaseInferred from experiment: ubiA
Schizosaccharomyces pombe 972h-: 4-hydroxybenzoate polyprenyltransferase: coq2
Synechocystis sp. PCC 6803: 4-hydroxybenzoate-nonaprenyl transferaseInferred from experiment: plqA

In Pathway: ubiquinol-9 biosynthesis (eukaryotic), ubiquinol-9 biosynthesis (prokaryotic), plastoquinol-9 biosynthesis II

Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.

Mass balance status: Balanced.

Enzyme Commission Primary Name: 4-hydroxybenzoate polyprenyltransferase

Enzyme Commission Synonyms: nonaprenyl-4-hydroxybenzoate transferase, 4-hydroxybenzoate transferase, p-hydroxybenzoate dimethylallyltransferase, p-hydroxybenzoate polyprenyltransferase, p-hydroxybenzoic acid-polyprenyl transferase, p-hydroxybenzoic-polyprenyl transferase, 4-hydroxybenzoate nonaprenyltransferase

Standard Gibbs Free Energy (ΔrG in kcal/mol): -16.910004Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
This enzyme, involved in the biosynthesis of ubiquinone, attaches a polyprenyl side chain to a 4-hydroxybenzoate ring, producing the first ubiquinone intermediate that is membrane bound. The number of isoprenoid subunits in the side chain varies in different species. The enzyme does not have any specificity concerning the length of the polyprenyl tail, and accepts tails of various lengths with similar efficiency [Melzer94, Forsgren04, Tran07a].

Citations: [Sadre11, Kalen90, Okada04]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reactions of [an isoprenoid diphosphate + 4-hydroxybenzoate = a 4-hydroxy-3-polyprenylbenzoate + diphosphate] (
i1: all-trans-octaprenyl diphosphate + 4-hydroxybenzoate → 3-octaprenyl-4-hydroxybenzoate + diphosphate (

i2: all-trans-decaprenyl diphosphate + 4-hydroxybenzoate → 3-decaprenyl-4-hydroxybenzoate + diphosphate (

i3: all-trans-heptaprenyl diphosphate + 4-hydroxybenzoate → 3-heptaprenyl-4-hydroxybenzoate + diphosphate (

i4: all-trans-nonaprenyl diphosphate + 4-hydroxybenzoate → 3-nonaprenyl-4-hydroxybenzoate + diphosphate (
i5: all-trans-hexaprenyl diphosphate + 4-hydroxybenzoate → 3-hexaprenyl-4-hydroxybenzoate + diphosphate (

i6: geranyl diphosphate + 4-hydroxybenzoate → 3-geranyl-4-hydroxybenzoate + diphosphate (

Unification Links: KEGG:R07273, Rhea:17709

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

Created 11-Jan-2012 by Caspi R, SRI International


Forsgren04: Forsgren M, Attersand A, Lake S, Grunler J, Swiezewska E, Dallner G, Climent I (2004). "Isolation and functional expression of human COQ2, a gene encoding a polyprenyl transferase involved in the synthesis of CoQ." Biochem J 382(Pt 2);519-26. PMID: 15153069

Kalen90: Kalen A, Appelkvist EL, Chojnacki T, Dallner G (1990). "Nonaprenyl-4-hydroxybenzoate transferase, an enzyme involved in ubiquinone biosynthesis, in the endoplasmic reticulum-Golgi system of rat liver." J Biol Chem 265(2);1158-64. PMID: 2295606

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

Melzer94: Melzer M, Heide L (1994). "Characterization of polyprenyldiphosphate: 4-hydroxybenzoate polyprenyltransferase from Escherichia coli." Biochim Biophys Acta 1994;1212(1);93-102. PMID: 8155731

Okada04: Okada K, Ohara K, Yazaki K, Nozaki K, Uchida N, Kawamukai M, Nojiri H, Yamane H (2004). "The AtPPT1 gene encoding 4-hydroxybenzoate polyprenyl diphosphate transferase in ubiquinone biosynthesis is required for embryo development in Arabidopsis thaliana." Plant Mol Biol 55(4);567-77. PMID: 15604701

Sadre11: Sadre R, Pfaff C, Buchkremer S (2011). "Plastoquinone-9 biosynthesis in cyanobacteria differs from that in plants and involves a novel 4-hydroxybenzoate solanesyltransferase." Biochem J. PMID: 22166075

Tran07a: Tran UC, Clarke CF (2007). "Endogenous synthesis of coenzyme Q in eukaryotes." Mitochondrion 7 Suppl;S62-71. PMID: 17482885

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 Pathway Tools version 19.5 (software by SRI International) on Tue May 3, 2016, biocyc14.