Identification of neoxanthin synthase as a carotenoid cyclase paralog
| Autor: | Bilal Camara, Alain d'Harlingue, Monto H. Kumagai, Florence Bouvier, Ralph A. Backhaus |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
chemistry.chemical_classification
ATP synthase biology fungi virus diseases food and beverages Neoxanthin synthase biochemical phenomena metabolism and nutrition Biochemistry Cyclase chemistry.chemical_compound chemistry Neoxanthin immune system diseases Complementary DNA Xanthophyll biology.protein Abscisic acid Violaxanthin |
| Zdroj: | European Journal of Biochemistry. 267:6346-6352 |
| ISSN: | 0014-2956 |
| DOI: | 10.1046/j.1432-1327.2000.01722.x |
| Popis: | Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similarities of NSY to two other closely related carotenogenic enzymes, lycopene cyclase (LCY) and capsanthin-capsorubin synthase (CCS). The identified tomato NSY cDNA (T.NSY) encodes a 56-kDa plastid-targeted protein that when expressed in Escherichia coli, catalyzes the conversion of violaxanthin to neoxanthin. In tobacco leaves that transiently express T.NSY, an increase in neoxanthin content with a concomitant decrease in violaxanthin is observed. NSY is structurally similar to LCY and CCS. However, in Cyanobacteria, the generally accepted progenitor of plastids, both CCS and NSY are absent while LCY is present. LCY catalyzes a simplified version of the reaction catalyzed by NSY and CCS suggesting that these two enzymes were remodeled from LCY during higher plant evolution to create new forms of oxidized carotenoids. |
| Databáze: | OpenAIRE |
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