MetaCyc Reaction:

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

Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. 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): -20.64 Inferred 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 [Lee97b].

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

i2: demethylmenaquinol-9 + S-adenosyl-L-methionine → menaquinol-9 + S-adenosyl-L-homocysteine + H+ (

i3: demethylmenaquinol-10 + S-adenosyl-L-methionine → menaquinol-10 + S-adenosyl-L-homocysteine + H+ (

i4: demethylmenaquinol-11 + S-adenosyl-L-methionine → menaquinol-11 + S-adenosyl-L-homocysteine + H+ (

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

i6: demethylmenaquinol-13 + S-adenosyl-L-methionine → menaquinol-13 + S-adenosyl-L-homocysteine + H+ (
i7: S-adenosyl-L-methionine + demethylmenaquinol-8 → S-adenosyl-L-homocysteine + menaquinol-8 + H+ (

i8: demethylmenaquinol-6 + S-adenosyl-L-methionine → menaquinol-6 + 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."

Lee97b: 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
Page generated by SRI International Pathway Tools version 19.0 on Mon Aug 3, 2015, BIOCYC14A.