Publications

• 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.

  Shimada H., Ohno R., Shibata M., Ikegami I., Onai K., Ohto M.A., Takamiya K.

  Phylloquinone, a substituted 1,4-naphthoquinone with an 18-carbon-saturated phytyl tail, functions as a bound one-electron carrier cofactor at the A1 site of photosystem I (PSI). A Feldmann tag line mutant, no. 2755 (designated as abc4 hereafter), showed pale-green young leaves and white old leave ... >> More

  Phylloquinone, a substituted 1,4-naphthoquinone with an 18-carbon-saturated phytyl tail, functions as a bound one-electron carrier cofactor at the A1 site of photosystem I (PSI). A Feldmann tag line mutant, no. 2755 (designated as abc4 hereafter), showed pale-green young leaves and white old leaves. The mutated nuclear gene encoded 1,4-dihydroxy-2-naphtoic acid phytyltransferase, an enzyme of phylloquinone biosynthesis, and high-performance liquid chromatography analysis revealed that the abc4 mutant contained no phylloquinone, and only about 3% plastoquinone. Photooxidation of P700 of PSI in the abc4 mutant was not observed, and reduced-versus-oxidized difference spectroscopy indicated that the abc4 mutant had no P700. The maximum quantum yield of photosystem II (PSII) in the abc4 mutant was much decreased, and the electron transfer from PSII to PSI in the abc4 mutant did not occur. For the pale-green leaves of the abc4 mutant plant, the ultrastructure of the chloroplasts was almost the same as that of the wild-type plant. However, the chloroplasts in the albino leaves of the mutant were smaller and had a lot of grana thylakoids and few stroma thylakoids. The amounts of PSI and PSII core subunits in the abc4 mutant were significantly decreased compared with those in the wild type. These results suggested that a deficiency of phylloquinone in PSI caused the abolishment of PSI and a partial defect of PSII due to a significant decrease of plastoquinone, but did not influence the ultrastructure of the chloroplasts in young leaves. << Less

  Plant J. 41:627-637(2005) [PubMed] [EuropePMC]

• 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.

  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., Chitnis P.R.

  Genes encoding enzymes of the biosynthetic pathway leading to phylloquinone, the secondary electron acceptor of photosystem (PS) I, were identified in Synechocystis sp. PCC 6803 by comparison with genes encoding enzymes of the menaquinone biosynthetic pathway in Escherichia coli. Targeted inactiva ... >> More

  Genes encoding enzymes of the biosynthetic pathway leading to phylloquinone, the secondary electron acceptor of photosystem (PS) I, were identified in Synechocystis sp. PCC 6803 by comparison with genes encoding enzymes of the menaquinone biosynthetic pathway in Escherichia coli. Targeted inactivation of the menA and menB genes, which code for phytyl transferase and 1,4-dihydroxy-2-naphthoate synthase, respectively, prevented the synthesis of phylloquinone, thereby confirming the participation of these two gene products in the biosynthetic pathway. The menA and menB mutants grow photoautotrophically under low light conditions (20 microE m(-2) s(-1)), with doubling times twice that of the wild type, but they are unable to grow under high light conditions (120 microE m(-2) s(-1)). The menA and menB mutants grow photoheterotrophically on media supplemented with glucose under low light conditions, with doubling times similar to that of the wild type, but they are unable to grow under high light conditions unless atrazine is present to inhibit PS II activity. The level of active PS II per cell in the menA and menB mutant strains is identical to that of the wild type, but the level of active PS I is about 50-60% that of the wild type as assayed by low temperature fluorescence, P700 photoactivity, and electron transfer rates. PS I complexes isolated from the menA and menB mutant strains contain the full complement of polypeptides, show photoreduction of F(A) and F(B) at 15 K, and support 82-84% of the wild type rate of electron transfer from cytochrome c(6) to flavodoxin. HPLC analyses show high levels of plastoquinone-9 in PS I complexes from the menA and menB mutants but not from the wild type. We propose that in the absence of phylloquinone, PS I recruits plastoquinone-9 into the A(1) site, where it functions as an efficient cofactor in electron transfer from A(0) to the iron-sulfur clusters. << Less

  J. Biol. Chem. 275:8523-8530(2000) [PubMed] [EuropePMC]

• A dedicated type II NADPH dehydrogenase performs the penultimate step in the biosynthesis of vitamin K1 in Synechocystis and Arabidopsis.

  Fatihi A., Latimer S., Schmollinger S., Block A., Dussault P.H., Vermaas W.F., Merchant S.S., Basset G.J.

  Mutation of Arabidopsis thaliana NAD(P)H DEHYDROGENASE C1 (NDC1; At5g08740) results in the accumulation of demethylphylloquinone, a late biosynthetic intermediate of vitamin K1. Gene coexpression and phylogenomics analyses showed that conserved functional associations occur between vitamin K biosy ... >> More

  Mutation of Arabidopsis thaliana NAD(P)H DEHYDROGENASE C1 (NDC1; At5g08740) results in the accumulation of demethylphylloquinone, a late biosynthetic intermediate of vitamin K1. Gene coexpression and phylogenomics analyses showed that conserved functional associations occur between vitamin K biosynthesis and NDC1 homologs throughout the prokaryotic and eukaryotic lineages. Deletion of Synechocystis ndbB, which encodes for one such homolog, resulted in the same defects as those observed in the cyanobacterial demethylnaphthoquinone methyltransferase knockout. Chemical modeling and assay of purified demethylnaphthoquinone methyltransferase demonstrated that, by virtue of the strong electrophilic nature of S-adenosyl-l-methionine, the transmethylation of the demethylated precursor of vitamin K is strictly dependent on the reduced form of its naphthoquinone ring. NDC1 was shown to catalyze such a prerequisite reduction by using NADPH and demethylphylloquinone as substrates and flavine adenine dinucleotide as a cofactor. NDC1 displayed Michaelis-Menten kinetics and was markedly inhibited by dicumarol, a competitive inhibitor of naphthoquinone oxidoreductases. These data demonstrate that the reduction of the demethylnaphthoquinone ring represents an authentic step in the biosynthetic pathway of vitamin K, that this reaction is enzymatically driven, and that a selection pressure is operating to retain type II NAD(P)H dehydrogenases in this process. << Less

  Plant Cell 27:1730-1741(2015) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.