EC
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1.10.99.3
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Transferred entry: | violaxanthin de-epoxidase. Now classified as EC 1.23.5.1, violaxanthin de-epoxidase.
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[EC 1.10.99.3 created 2005, deleted 2014] |
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EC
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1.14.13.90
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Transferred entry: | zeaxanthin epoxidase. Now EC 1.14.15.21, zeaxanthin epoxidase
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[EC 1.14.13.90 created 2005, deleted 2016] |
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EC |
1.14.15.21 |
Accepted name: |
zeaxanthin epoxidase |
Reaction: |
zeaxanthin + 4 reduced ferredoxin [iron-sulfur] cluster + 4 H+ + 2 O2 = violaxanthin + 4 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O (overall reaction) (1a) zeaxanthin + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ + O2 = antheraxanthin + 2 oxidized ferredoxin [iron-sulfur] cluster + H2O (1b) antheraxanthin + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ + O2 = violaxanthin + 2 oxidized ferredoxin [iron-sulfur] cluster + H2O |
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For diagram of the xanthophyll cycle, click here |
Other name(s): |
Zea-epoxidase |
Systematic name: |
zeaxanthin,reduced ferredoxin:oxygen oxidoreductase |
Comments: |
A flavoprotein (FAD) that is active under conditions of low light. Along with EC 1.23.5.1, violaxanthin de-epoxidase, this enzyme forms part of the xanthophyll (or violaxanthin) cycle, which is involved in protecting the plant against damage by excess light. It will also epoxidize lutein in some higher-plant species. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 149718-34-3 |
References: |
1. |
Buch, K., Stransky, H. and Hager, A. FAD is a further essential cofactor of the NAD(P)H and O2-dependent zeaxanthin-epoxidase. FEBS Lett. 376 (1995) 45–48. [DOI] [PMID: 8521963] |
2. |
Bugos, R.C., Hieber, A.D. and Yamamoto, H.Y. Xanthophyll cycle enzymes are members of the lipocalin family, the first identified from plants. J. Biol. Chem. 273 (1998) 15321–15324. [DOI] [PMID: 9624110] |
3. |
Thompson, A.J., Jackson, A.C., Parker, R.A., Morpeth, D.R., Burbidge, A. and Taylor, I.B. Abscisic acid biosynthesis in tomato: regulation of zeaxanthin epoxidase and 9-cis-epoxycarotenoid dioxygenase mRNAs by light/dark cycles, water stress and abscisic acid. Plant Mol. Biol. 42 (2000) 833–845. [PMID: 10890531] |
4. |
Hieber, A.D., Bugos, R.C. and Yamamoto, H.Y. Plant lipocalins: violaxanthin de-epoxidase and zeaxanthin epoxidase. Biochim. Biophys. Acta 1482 (2000) 84–91. [DOI] [PMID: 11058750] |
5. |
Frommolt, R., Goss, R. and Wilhelm, C. The de-epoxidase and epoxidase reactions of Mantoniella squamata (Prasinophyceae) exhibit different substrate-specific reaction kinetics compared to spinach. Planta 213 (2001) 446–456. [PMID: 11506368] |
6. |
Frommolt, R., Goss, R. and Wilhelm, C. Erratum Report. The de-epoxidase and epoxidase reactions of Mantoniella squamata (Prasinophyceae) exhibit different substrate-specific reaction kinetics compared to spinach. Planta 213 (2001) 492. |
7. |
Matsubara, S., Morosinotto, T., Bassi, R., Christian, A.L., Fischer-Schliebs, E., Luttge, U., Orthen, B., Franco, A.C., Scarano, F.R., Forster, B., Pogson, B.J. and Osmond, C.B. Occurrence of the lutein-epoxide cycle in mistletoes of the Loranthaceae and Viscaceae. Planta 217 (2003) 868–879. [DOI] [PMID: 12844265] |
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[EC 1.14.15.21 created 2005 as EC 1.14.13.90, transferred 2016 to EC 1.14.15.21] |
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EC |
1.23.5.1 |
Accepted name: |
violaxanthin de-epoxidase |
Reaction: |
violaxanthin + 2 L-ascorbate = zeaxanthin + 2 L-dehydroascorbate + 2 H2O (overall reaction) (1a) violaxanthin + L-ascorbate = antheraxanthin + L-dehydroascorbate + H2O (1b) antheraxanthin + L-ascorbate = zeaxanthin + L-dehydroascorbate + H2O |
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For diagram of the xanthophyll cycle, click here |
Glossary: |
violaxanthin = (3S,3′S,5R,5′R,6S,6′S)-5,6:5′,6′-diepoxy-5,5′,6,6′-tetrahydro-β,β-carotene-3,3′-diol
antheraxanthin = (3R,3′S,5′R,6′S)-5′,6′-epoxy-5′,6′-dihydro-β,β-carotene-3,3′-diol
zeaxanthin = (3R,3′R)-β,β-carotene-3,3′-diol |
Other name(s): |
VDE |
Systematic name: |
violaxanthin:ascorbate oxidoreductase |
Comments: |
Along with EC 1.14.15.21, zeaxanthin epoxidase, this enzyme forms part of the xanthophyll (or violaxanthin) cycle for controlling the concentration of zeaxanthin in chloroplasts. It is activated by a low pH of the thylakoid lumen (produced by high light intensity). Zeaxanthin induces the dissipation of excitation energy in the chlorophyll of the light-harvesting protein complex of photosystem II. In higher plants the enzyme reacts with all-trans-diepoxides, such as violaxanthin, and all-trans-monoepoxides, but in the alga Mantoniella squamata, only the diepoxides are good substrates. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 57534-73-3 |
References: |
1. |
Yamamoto, H.Y. and Higashi, R.M. Violaxanthin de-epoxidase. Lipid composition and substrate specificity. Arch. Biochem. Biophys. 190 (1978) 514–522. [DOI] [PMID: 102251] |
2. |
Rockholm, D.C. and Yamamoto, H.Y. Violaxanthin de-epoxidase. Plant Physiol. 110 (1996) 697–703. [PMID: 8742341] |
3. |
Bugos, R.C., Hieber, A.D. and Yamamoto, H.Y. Xanthophyll cycle enzymes are members of the lipocalin family, the first identified from plants. J. Biol. Chem. 273 (1998) 15321–15324. [DOI] [PMID: 9624110] |
4. |
Kuwabara, T., Hasegawa, M., Kawano, M. and Takaichi, S. Characterization of violaxanthin de-epoxidase purified in the presence of Tween 20: effects of dithiothreitol and pepstatin A. Plant Cell Physiol. 40 (1999) 1119–1126. [PMID: 10635115] |
5. |
Latowski, D., Kruk, J., Burda, K., Skrzynecka-Jaskierm, M., Kostecka-Gugala, A. and Strzalka, K. Kinetics of violaxanthin de-epoxidation by violaxanthin de-epoxidase, a xanthophyll cycle enzyme, is regulated by membrane fluidity in model lipid bilayers. Eur. J. Biochem. 269 (2002) 4656–4665. [DOI] [PMID: 12230579] |
6. |
Goss, R. Substrate specificity of the violaxanthin de-epoxidase of the primitive green alga Mantoniella squamata (Prasinophyceae). Planta 217 (2003) 801–812. [DOI] [PMID: 12748855] |
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Latowski, D., Akerlund, H.E. and Strzalka, K. Violaxanthin de-epoxidase, the xanthophyll cycle enzyme, requires lipid inverted hexagonal structures for its activity. Biochemistry 43 (2004) 4417–4420. [DOI] [PMID: 15078086] |
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[EC 1.23.5.1 created 2005 as EC 1.10.99.3, transferred 2015 to EC 1.23.5.1] |
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EC |
5.3.99.8 |
Accepted name: |
capsanthin/capsorubin synthase |
Reaction: |
(1) violaxanthin = capsorubin (2) antheraxanthin = capsanthin |
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For diagram of the biosynthesis of capsanthin, capsarubin and neoxanthin, click here and for diagram of carotenoid epoxide rearrangements, click here |
Other name(s): |
CCS; ketoxanthophyll synthase; capsanthin-capsorubin synthase |
Systematic name: |
violaxanthin—capsorubin isomerase (ketone-forming) |
Comments: |
This multifunctional enzyme is induced during chromoplast differentiation in plants [1]. Isomerization of the epoxide ring of violaxanthin gives the cyclopentyl-ketone of capsorubin or capsanthin. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 162032-85-1 |
References: |
1. |
Bouvier, F., Hugueney, P., d'Harlingue, A., Kuntz, M. and Camara, B. Xanthophyll biosynthesis in chromoplasts: isolation and molecular cloning of an enzyme catalyzing the conversion of 5,6-epoxycarotenoid into ketocarotenoid. Plant J. 6 (1994) 45–54. [DOI] [PMID: 7920703] |
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Lefebvre, V., Kuntz, M., Camara, B. and Palloix, A. The capsanthin-capsorubin synthase gene: a candidate gene for the y locus controlling the red fruit colour in pepper. Plant Mol. Biol. 36 (1998) 785–789. [PMID: 9526511] |
3. |
Xu, C.J., Chen, D.M. and Zhang, S.L. [Molecular cloning of full length capsanthin/capsorubin synthase
homologous gene from orange (Citrus sinensis)] Shi Yan Sheng Wu Xue Bao 34 (2001) 147–150. [PMID: 12549109] (in Chinese) |
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[EC 5.3.99.8 created 2005] |
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