Studies on the expression of NDH-H, a subunit of the NAD(P)H-plastoquinone-oxidoreductase of higher-plant chloroplasts
Autor: | Peter Westhoff, Susanne Berger, Klaus Steinmüller, Ulrike Ellersiek |
---|---|
Rok vydání: | 1993 |
Předmět: | |
Zdroj: | Planta. 190 |
ISSN: | 1432-2048 0032-0935 |
Popis: | The plastid genomes of higher plants contain eleven reading frames (ndhA-K) that are homologous to genes encoding subunits of the mitochondrial NADH-ubiquinone-oxidoreductase (complex I). The carboxyterminal end of the NDH-H subunit from rice (Oryza sativa L.) was expressed as a fusion protein in Escherichia coli and antibodies against the fusion protein were generated in rabbits. The antibody was used to study the expression of NDH-H, and the following results were obtained: (i) NDH-H is expressed in mono- and dicotyledonous plants, (ii) NDH-H is localized on the stroma lamellae of the thylakoid membrane and (iii) NDH-H is expressed in etioplasts. Together with the finding that two other ndh genes (ndhI and ndhK) are expressed in plastids, these results point to the existence of an NAD(P)H-plastoquinone-oxidoreductase on the thylakoid membrane. The possible function of the enzyme in plastids is discussed and it is suggested that it works in balancing the ATP/ADP and the NADPH/NADP ratios during changing external (i.e. light) or internal (i.e. ATP and NADPH demands of biosynthetic pathways of the plastid) conditions. |
Databáze: | OpenAIRE |
Externí odkaz: |