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.
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. [PMID: 26023160]
[EC created 2015]
Accepted name: 2-carboxy-1,4-naphthoquinone phytyltransferase
Reaction: phytyl diphosphate + 2-carboxy-1,4-naphthoquinone = demethylphylloquinone + diphosphate + CO2
Glossary: 2-carboxy-1,4-naphthoquinone = 1,4-dioxo-2-naphthoic acid
Other name(s): menA (gene name); ABC4 (gene name); 1,4-dioxo-2-naphthoate phytyltransferase; 1,4-diketo-2-naphthoate phytyltransferase
Systematic name: phytyl-diphosphate:2-carboxy-1,4-naphthoquinone phytyltransferase
Comments: This enzyme, found in plants and cyanobacteria, catalyses a step in the synthesis of phylloquinone (vitamin K1), an electron carrier associated with photosystem I. The enzyme catalyses the transfer of the phytyl chain synthesized by EC, geranylgeranyl diphosphate reductase, to 2-carboxy-1,4-naphthoquinone.
1.  Johnson, T.W., Shen, G., Zybailov, B., Kolling, D., Reategui, R., Beauparlant, S., Vassiliev, I.R., Bryant, D.A., Jones, A.D., Golbeck, J.H. and Chitnis, P.R. 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 (2000) 8523–8530. [PMID: 10722690]
2.  Shimada, H., Ohno, R., Shibata, M., Ikegami, I., Onai, K., Ohto, M.A. and Takamiya, K. 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 (2005) 627–637. [PMID: 15686525]
[EC created 2015]