This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: vitamin K1 biosynthesis, phylloquinone biosynthesis
|Superclasses:||Biosynthesis → Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis → Quinol and Quinone Biosynthesis → Phylloquinol Biosynthesis|
|Biosynthesis → Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis → Vitamins Biosynthesis|
phylloquinone (vitamin K1) is a naphthoquinone that acts as the electron transfer cofactor (known as A1) of photosystem I (PS I) in higher plants and cyanobacteria. It is very similar to a menaquinone (vitamin K2), a naphthoquinone which is common in non-photosynthetic microbes, in which it serves in anaerobic electron transport systems [Sharma96]. The only difference between phyloquinone and menaquinone is in the polyprenyl tail. Menaquinones contain 1-14 isoprene units, while phyloquinone contains a phytyl side chain of 4 units [Shimada05].
The biosynthesis of phylloquinone was studied in detail in the cyanobacterium Synechocystis sp. PCC 6803 and the genes encoding enzymes of this pathway were identified by comparison with genes encoding enzymes of the menaquinone biosynthetic pathway in Escherichia coli (see superpathway of menaquinol-8 biosynthesis I) [Sharma96]. With the isolation and functional confirmation of the homolog genes in Synechocystis encoding for phytyl transferase, 1,4-dihydroxy-2-naphthoate synthase [Johnson00], 2-phytyl-1,4-naphthoquinone methyltransferase [Sakuragi02], SHCHC synthase and o-succinylbenzoic acid-CoA synthase [Johnson03] most of the enzymatic steps of the phylloquinone bisoynthesis have been determined and proven to be highly identical with those in the menaquinone biosynthesis.
The biosynthesis of certain components of the multienzyme complex PS I of cyanobacteria and plants such as phylloquinone have been found to follow analogous routes including corresponding enzymatic activities [Heide82] [Kolkmann87, Simantiras89, Simantiras91] which reflects the function and phylogenetic origin of PS I in photosynthetic species.
About This Pathway
The enzymatic steps involved in the biosynthesis of phylloquinone in cyanobacteria and plants are almost identical to the biosynthetic route leading to the microbial complement menaquinone. However, it has been demonstrated in cell suspensions of Galium mollugo that the formation of the key intermediate 1,4-dihydroxy-2-naphtoate (DHNA) preferably occurs via 4-(2'-carboxyphenyl)-4-oxobutyryl CoA. The o-succinylbenzoate CoA ligase catalyzes the attachment of the CoA to the C1 of the side chain of o-succinylbenzoate (OSB), creating the "aliphatic" variant of o-succinylbenzoate-CoA [Simantiras91] instead of forming the "aromatic" isomer where the CoA ester is attached to the aromatic carboxyl group.
The following reaction, the prenylation of DHNA is the discernible step between phylloquinone and menaquinone biosynthesis. The DHNA phytyltransferase catalyzes the attachment of a C-20 phytyl side chain leading to demethylphylloquinone [Shimada05], whereas microbial DHNA prenyltransferases attache a multiprenyl side chain, forming demethylmenaquinones. The length of the side chain varies among different species, but the most common is that of 7 prenyl units, resulting in formation of demethylmenaquinone-7.
It has been found that phylloquinone is not absolutely required for efficient electron transfer in PS I [Johnson00]. In Synechocystis sp. PCC 6803 benzoquinones such as plastoquinone-9, which usually act as secondary electron acceptors in PS II [Johnson01, Sakuragi05], can efficiently replace phylloquinone in the A1-site of PS I as a one-electron cofactor. However, as shown in an Arabidopsis mutant the deficiency of phylloquinone causes distortions in the thylakoid structure of chloroplasts, may abolish PS I, and affects the functionality of PS II [Shimada05].
Superpathways: superpathway of phylloquinol biosynthesis
Unification Links: AraCyc:PWY-5027
Fujimoto12: Fujimoto N., Kosaka T., Yamada M. (2012). "Menaquinone as Well as Ubiquinone as a Crucial Component in the Escherichia coli Respiratory Chain." Chapter 10 in Chemical Biology, edited by D Ekinci, ISBN 978-953-51-0049-2.
Heide82: Heide L, Kolkmann R, Arendt S, Leistner E (1982). "Enzymic synthesis of o-succinylbenzoyl-CoA in cell-free extracts of anthraquinone producing Galium mollugo L. cell suspension cultures." Plant Cell Reports, 1, 180-182.
Johnson00: Johnson TW, Shen G, Zybailov B, Kolling D, Reategui R, Beauparlant S, Vassiliev IR, Bryant DA, Jones AD, Golbeck JH, Chitnis PR (2000). "Recruitment of a foreign quinone into the A(1) site of photosystem I. I. Genetic and physiological characterization of phylloquinone biosynthetic pathway mutants in Synechocystis sp. pcc 6803." J Biol Chem 275(12);8523-30. PMID: 10722690
Johnson01: Johnson TW, Zybailov B, Jones AD, Bittl R, Zech S, Stehlik D, Golbeck JH, Chitnis PR (2001). "Recruitment of a foreign quinone into the A1 site of photosystem I. In vivo replacement of plastoquinone-9 by media-supplemented naphthoquinones in phylloquinone biosynthetic pathway mutants of Synechocystis sp. PCC 6803." J Biol Chem 276(43);39512-21. PMID: 11470786
Johnson03: Johnson TW, Naithani S, Steward Jr C, Zybailov B, Jones AD, Golbeck JH, Chitnis PR (2003). "The menD and menE homologs code for 2-succinyl-6-hydroxyl-2, 4-cyclohexadiene-1-carboxylate synthase and O-succinylbenzoic acid-CoA synthase in the phylloquinone biosynthetic pathway of Synechocystis sp. PCC 6803." Biochimica et Biophysica Acta, 1557, 67-76.
Sakuragi02: Sakuragi Y, Zybailov B, Shen G, Jones AD, Chitnis PR, van der Est A, Bittl R, Zech S, Stehlik D, Golbeck JH, Bryant DA (2002). "Insertional inactivation of the menG gene, encoding 2-phytyl-1,4-naphthoquinone methyltransferase of Synechocystis sp. PCC 6803, results in the incorporation of 2-phytyl-1,4-naphthoquinone into the A(1) site and alteration of the equilibrium constant between A(1) and F(X) in photosystem I." Biochemistry 41(1);394-405. PMID: 11772039
Sakuragi05: Sakuragi Y, Zybailov B, Shen G, Bryant DA, Golbeck JH, Diner BA, Karygina I, Pushkar Y, Stehlik D (2005). "Recruitment of a foreign quinone into the A1 site of photosystem I. Characterization of a menB rubA double deletion mutant in Synechococcus sp. PCC 7002 devoid of FX, FA, and FB and containing plastoquinone or exchanged 9,10-anthraquinone." J Biol Chem 280(13);12371-81. PMID: 15681848
Sharma96: Sharma V, Hudspeth ME, Meganathan R (1996). "Menaquinone (vitamin K2) biosynthesis: localization and characterization of the menE gene from Escherichia coli." Gene 1996;168(1);43-8. PMID: 8626063
Shimada05: Shimada H, Ohno R, Shibata M, Ikegami I, Onai K, Ohto MA, Takamiya K (2005). "Inactivation and deficiency of core proteins of photosystems I and II caused by genetical phylloquinone and plastoquinone deficiency but retained lamellar structure in a T-DNA mutant of Arabidopsis.." Plant J 41(4);627-37. PMID: 15686525
Simantiras89: Simantiras M, Leistner E (1989). "Formation of o-succinylbenzoic acid from iso-chorismic acid in protein extracts from anthraquinone-producing plant cell suspension cultures." Phytochemistry, 28, 1381-1382.
Simantiras91: Simantiras M, Leistner E (1991). "Cell free synthesis of O-succinylbenzoic acid in protein extracts from anthraquinone and phylloquinone (vitamin K1) producing plant cell suspension cultures. Occurrence of intermediates between isochorismic and O-succinylbenzoic acid." Z. Naturforsch., 46c, 364-370.
Kaneko96: Kaneko T, Sato S, Kotani H, Tanaka A, Asamizu E, Nakamura Y, Miyajima N, Hirosawa M, Sugiura M, Sasamoto S, Kimura T, Hosouchi T, Matsuno A, Muraki A, Nakazaki N, Naruo K, Okumura S, Shimpo S, Takeuchi C, Wada T, Watanabe A, Yamada M, Yasuda M, Tabata S (1996). "Sequence analysis of the genome of the unicellular cyanobacterium Synechocystis sp. strain PCC6803. II. Sequence determination of the entire genome and assignment of potential protein-coding regions." DNA Res 1996;3(3);109-36. PMID: 8905231
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