EC |
1.6.5.12 |
Accepted name: |
demethylphylloquinone reductase |
Reaction: |
demethylphylloquinone + NADPH + H+ = demethylphylloquinol + NADP+ |
Glossary: |
demethylphylloquinone = 2-phytyl-1,4-naphthoquinone |
Other name(s): |
ndbB (gene name); NDC1 (gene name); demethylphylloquinone:NADPH oxidoreductase |
Systematic name: |
NADPH:demethylphylloquinone oxidoreductase |
Comments: |
The enzyme, found in plants and cyanobacteria, is involved in the biosynthesis of phylloquinone (vitamin K1), an electron carrier associated with photosystem I. The enzyme is a type II NADPH dehydrogenase and requires a flavine adenine dinucleotide cofactor. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Fatihi, A., Latimer, S., Schmollinger, S., Block, A., Dussault, P.H., Vermaas, W.F., Merchant, S.S. and Basset, G.J. A dedicated type II NADPH dehydrogenase performs the penultimate step in the biosynthesis of vitamin K1 in Synechocystis and Arabidopsis. Plant Cell 27 (2015) 1730–1741. [DOI] [PMID: 26023160] |
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[EC 1.6.5.12 created 2015] |
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EC |
2.1.1.329 |
Accepted name: |
demethylphylloquinol methyltransferase |
Reaction: |
S-adenosyl-L-methionine + demethylphylloquinol = S-adenosyl-L-homocysteine + phylloquinol |
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For diagram of vitamin K biosynthesis, click here |
Glossary: |
demethylphylloquinol = 2-phytyl-1,4-naphthoquinol
phylloquinol = 2-methyl-3-phytyl-1,4-naphthoquinol = vitamin K1 |
Other name(s): |
menG (gene name); 2-phytyl-1,4-naphthoquinol methyltransferase |
Systematic name: |
S-adenosyl-L-methionine:2-phytyl-1,4-naphthoquinol C-methyltransferase |
Comments: |
The enzyme, found in plants and cyanobacteria, catalyses the final step in the biosynthesis of phylloquinone (vitamin K1), an electron carrier associated with photosystem I. The enzyme is specific for the quinol form of the substrate, and does not act on the quinone form [3]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Sakuragi, Y., Zybailov, B., Shen, G., Jones, A.D., Chitnis, P.R., van der Est, A., Bittl, R., Zech, S., Stehlik, D., Golbeck, J.H. and Bryant, D.A. 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 A1 site and alteration of the equilibrium constant between A1 and F(X) in photosystem I. Biochemistry 41 (2002) 394–405. [DOI] [PMID: 11772039] |
2. |
Lohmann, A., Schottler, M.A., Brehelin, C., Kessler, F., Bock, R., Cahoon, E.B. and Dormann, P. Deficiency in phylloquinone (vitamin K1) methylation affects prenyl quinone distribution, photosystem I abundance, and anthocyanin accumulation in the Arabidopsis AtmenG mutant. J. Biol. Chem. 281 (2006) 40461–40472. [DOI] [PMID: 17082184] |
3. |
Fatihi, A., Latimer, S., Schmollinger, S., Block, A., Dussault, P.H., Vermaas, W.F., Merchant, S.S. and Basset, G.J. A dedicated type II NADPH dehydrogenase performs the penultimate step in the biosynthesis of vitamin K1 in Synechocystis and Arabidopsis. Plant Cell 27 (2015) 1730–1741. [DOI] [PMID: 26023160] |
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[EC 2.1.1.329 created 2016] |
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