MetaCyc Reaction:

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

EC Number:

Enzymes and Genes:

Geobacillus stearothermophilus: S-adenosylmethionine:2-demethylmenaquinol methyltransferase: menH
Mycobacterium phlei: S-adenosylmethionine:2-demethylmenaquinol methyltransferase

In Pathway: menaquinol-13 biosynthesis

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 direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Direct generic reaction:
S-adenosyl-L-methionine + a demethylmenaquinol → S-adenosyl-L-homocysteine + a menaquinol + H+ (

Enzyme Commission Primary Name: demethylmenaquinone methyltransferase

Enzyme Commission Synonyms: S-adenosyl-L-methione-DMK methyltransferase, demethylmenaquinone C-methylase, 2-heptaprenyl-1,4-naphthoquinone methyltransferase, 2-demethylmenaquinone methyltransferase, S-adenosyl-L-methione:2-demethylmenaquinone methyltransferase

Standard Gibbs Free Energy (ΔrG in kcal/mol): -20.64Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
The enzyme catalyses the last step in menaquinone biosynthesis. It is able to accept substrates with varying polyprenyl side chain length (the chain length is determined by polyprenyl diphosphate synthase) [KoikeTakeshita97]. The enzyme from E. coli also catalyses the conversion of 2-octaprenyl-6-methoxy-1,4-benzoquinone to 2-octaprenyl-3-methyl-6-methoxy-1,4-benzoquinone during the biosynthesis of ubiquinone [Lee97].

Citations: [Wissenbach92, Catala70]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reactions of [S-adenosyl-L-methionine + a demethylmenaquinol → S-adenosyl-L-homocysteine + a menaquinol + H+] (
i1: demethylmenaquinol-10 + S-adenosyl-L-methionine → menaquinol-10 + S-adenosyl-L-homocysteine + H+ (

i2: demethylmenaquinol-6 + S-adenosyl-L-methionine → menaquinol-6 + S-adenosyl-L-homocysteine + H+ (

i3: demethylmenaquinol-11 + S-adenosyl-L-methionine → menaquinol-11 + S-adenosyl-L-homocysteine + H+ (

i4: demethylmenaquinol-7 + S-adenosyl-L-methionine → menaquinol-7 + S-adenosyl-L-homocysteine + H+ (

i5: demethylmenaquinol-12 + S-adenosyl-L-methionine → menaquinol-12 + S-adenosyl-L-homocysteine + H+ (

i6: demethylmenaquinol-9 + S-adenosyl-L-methionine → menaquinol-9 + S-adenosyl-L-homocysteine + H+ (

i7: S-adenosyl-L-methionine + demethylmenaquinol-8 → S-adenosyl-L-homocysteine + menaquinol-8 + H+ (

i8: demethylmenaquinol-13 + S-adenosyl-L-methionine → menaquinol-13 + S-adenosyl-L-homocysteine + H+ (

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


Catala70: Catala F, Azerad R, Lederer E (1970). "[Properties of demethylmenaquinone C-methylase from Mycobacterium phlei]." Int Z Vitaminforsch 40(3);363-73. PMID: 5450997

KoikeTakeshita97: Koike-Takeshita A, Koyama T, Ogura K (1997). "Identification of a novel gene cluster participating in menaquinone (vitamin K2) biosynthesis. Cloning and sequence determination of the 2-heptaprenyl-1,4-naphthoquinone methyltransferase gene of Bacillus stearothermophilus." J Biol Chem 272(19);12380-3. PMID: 9139683

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

Lee97: Lee PT, Hsu AY, Ha HT, Clarke CF (1997). "A C-methyltransferase involved in both ubiquinone and menaquinone biosynthesis: isolation and identification of the Escherichia coli ubiE gene." J Bacteriol 1997;179(5);1748-54. PMID: 9045837

Wissenbach92: Wissenbach U, Ternes D, Unden G (1992). "An Escherichia coli mutant containing only demethylmenaquinone, but no menaquinone: effects on fumarate, dimethylsulfoxide, trimethylamine N-oxide and nitrate respiration." Arch Microbiol 1992;158(1);68-73. PMID: 1444716

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
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