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Early Steps in the Biosynthesis of NAD in Arabidopsis Start with Aspartate and Occur in the Plastid.
- Source :
-
Plant Physiology . Jul2006, Vol. 141 Issue 3, p851-857. 7p. 3 Diagrams. - Publication Year :
- 2006
-
Abstract
- NAD is a ubiquitous coenzyme involved in oxidation-reduction reactions and is synthesized by way of quinolinate. Animals and some bacteria synthesize quinolinate from tryptophan, whereas other bacteria synthesize quinolinate from aspartate (Asp) using L-Asp oxidase and quinolinate synthase. We show here that Arabidopsis (Arabidopsis thaliana) uses the Asp-to-quinolinate pathway. The Arabidopsis L-Asp oxidase or quinolinate synthase gene complemented the Escherichia coli mutant defective in the corresponding gene, and T-DNA-based disruption of either of these genes, as well as of the gene coding for the enzyme quinolinate phosphoribosyltransferase, was embryo lethal. An analysis of functional green fluorescent protein-fused constructs and in vitro assays of uptake into isolated chloroplasts demonstrated that these three enzymes are located in the plastid. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00320889
- Volume :
- 141
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Plant Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 21835107
- Full Text :
- https://doi.org/10.1104/pp.106.081091