Genome Property Definition Page

Accession

GenProp0058

Name

menaquinone biosynthesis via SEPHCHC

Type

PATHWAY

Description

Menaquinone (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 Role

Menaquinone and ubiquinone

Parent Property

GenProp0836: 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 References

KEGG: Ubiquinone metabolism

Gene Ontology Term

GO:0009234: menaquinone biosynthetic process (biological_process)

Components

Step Name	Step Num	Required	Evidence (Method)	Evidence Go Terms
isochorismate synthase	1_menF	YES	TIGR00543 (HMM): isochorismate synthase
SEPHCHC synthase	2_menD	YES	TIGR00173 (HMM): 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylic-acid synthase	GO:0009234: menaquinone biosynthetic process
demethylmenaquinone methyltransferase	7	NO	ubiE (gene_sym) TIGR01934 (HMM): ubiquinone/menaquinone biosynthesis methyltransferase	GO:0009234: menaquinone biosynthetic process
1,4-dihydroxy-2-naphthoate prenyl-transferase	menA	YES	menA (gene_sym) TIGR00751 (HMM): 1,4-dihydroxy-2-naphthoate octaprenyltransferase	GO:0009234: menaquinone biosynthetic process GO:0009234: menaquinone biosynthetic process
naphthoate synthase	menB	YES	TIGR01929 (HMM): naphthoate synthase	GO:0009234: menaquinone biosynthetic process
o-succinylbenzoate synthase	menC	YES	menC (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 ligase	menE	YES	TIGR01923 (HMM): O-succinylbenzoate-CoA ligase	GO:0009234: menaquinone biosynthetic process
SHCHC synthase	menH	NO	TIGR03695 (HMM): 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase	GO:0009234: menaquinone biosynthetic process

Parent Properties

Accession	Name
GenProp0836	menaquinone biosynthesis

Sibling Properties

Accession	Name
GenProp0829	menaquinone biosynthesis via futalosine