Genome Property Definition Page

Namemenaquinone biosynthesis via SEPHCHC
DescriptionMenaquinone (also known as Vitamin K2) is one of the quinone cofactors which play an essential role in hydrogen transfer reactions, particularly during anaerobic respiration. Menaquinone in E. coli and various other bacteria is synthesized from chorismate, 2-oxoglutarate, polyprenyl-pyrophosphate and S-adenosylmethionine. A very similar molecule (phylloquinone, vitamin K1) is found in cyanobacteria and plants which contains a shorter isoprenoid (phytyl) chain which in which three of the four double bonds are reduced. In animals, both vitamins K1 and K2 act as cofactors for gamma-carboxylation of glutamate (Glu -> Gla) which is critical for coagulation factors. Note that an alternative pathway to menaquinone biosynthesis operates in Helicobacter pylori, Campylobacter jejuni, Streptomyces, and other species (see PMID:18801996). That pathway is not described here.
JCVI RoleMenaquinone and ubiquinone
Parent PropertyGenProp0836: menaquinone biosynthesis
Literature References
[ 1 ] Jiang M, Chen X, Guo ZF, Cao Y, Chen M, Guo Z   Identification and characterization of (1R,6R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase in the menaquinone biosynthesis of Escherichia coli.   Biochemistry. 2008 Mar 18;47(11):3426-34.  PMID 18284213
[ 2 ] Jiang M, Cao Y, Guo ZF, Chen M, Chen X, Guo Z   Menaquinone biosynthesis in Escherichia coli: identification of 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate as a novel intermediate and re-evaluation of MenD activity.   Biochemistry. 2007 Sep 25;46(38):10979-89.  PMID 17760421
Web ReferencesKEGG: Ubiquinone metabolism
Gene Ontology TermGO:0009234: menaquinone biosynthetic process (biological_process)

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
isochorismate synthase1_menFYESTIGR00543 (HMM): isochorismate synthase
SEPHCHC synthase2_menDYESTIGR00173 (HMM): 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylic-acid synthaseGO:0009234: menaquinone biosynthetic process
demethylmenaquinone methyltransferase7NOubiE (gene_sym)

TIGR01934 (HMM): ubiquinone/menaquinone biosynthesis methyltransferase
GO:0009234: menaquinone biosynthetic process
1,4-dihydroxy-2-naphthoate prenyl-transferasemenAYESmenA (gene_sym)

TIGR00751 (HMM): 1,4-dihydroxy-2-naphthoate octaprenyltransferase
GO:0009234: menaquinone biosynthetic process
GO:0009234: menaquinone biosynthetic process
naphthoate synthasemenBYESTIGR01929 (HMM): naphthoate synthaseGO:0009234: menaquinone biosynthetic process
o-succinylbenzoate synthasemenCYESmenC (gene_sym)

TIGR01927 (HMM): o-succinylbenzoate synthase
TIGR01928 (HMM): o-succinylbenzoate synthase
GO:0009234: menaquinone biosynthetic process
GO:0009234: menaquinone biosynthetic process
GO:0009234: menaquinone biosynthetic process
o-succinylbenzoate--CoA ligasemenEYESTIGR01923 (HMM): O-succinylbenzoate-CoA ligaseGO:0009234: menaquinone biosynthetic process
SHCHC synthasemenHNOTIGR03695 (HMM): 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthaseGO:0009234: menaquinone biosynthetic process

Parent Properties
GenProp0836menaquinone biosynthesis

Sibling Properties
GenProp0829menaquinone biosynthesis via futalosine