The NADH-binding subunit of respiratory chain complex I is nuclear-encoded in plants and identified only in mitochondria
Precursor proteins translated in vitro from the cDNA are imported into isolated potato mitochondria in a ΔΨ-dependent manner. The processed translation product has an apparent molecular mass of 55 kDa, identical to the mature protein present in the purified plant mitochondrial complex I. However, the in-vitro translated protein is not imported into isolated chloroplasts. To further investigate whether the complex I-like enzyme in chloroplasts contains an analogous subunit for binding of NAD(P)H, different plastid protein fractions were tested with a polyclonal antiserum directed against the bovine 51 kDa NADH-binding subunit. In none of the different thylakoid or stroma protein fractions analysed were specific crossreactive polypeptides detected. These results are discussed particularly with respect to the structure of a potential complex I in chloroplasts and the nature of its acceptor site.
Document Type: Research Article
Affiliations: 1: Institut für Genbiologische Forschung Berlin, Ihnestrasse 63, D-14195 Berlin, Germany 2: Universität Ulm, Allgemeine Botanik, Albert-Einstein-Allee, D-89069 Ulm, Germany
Publication date: November 1, 1996