title: Cyanobacteria contain a mitochondrial complex I-homologous NADH-dehydrogenase.
abstract: Thylakoid and cytoplasmic membranes of the cyanobacterium Synechocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhK and ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADH-ubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria. The NADH-dehydrogenase can be solubilized with the detergent beta-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex.
authors.affiliation: Institut für Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität Düsseldorf, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Berger
authors.forename: U
authors.initials: U
authors.lastname: Ellersiek
authors.forename: K
authors.initials: K
authors.lastname: Steinmüller
mesh_terms: D002874:Chromosome Mapping; D000458:Cyanobacteria / Q000201:enzymology* / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008928:Mitochondria / Q000201:enzymology*; D009245:NADH Dehydrogenase / Q000032:analysis*; D012402:Rotenone / Q000494:pharmacology
chemical_list: D012402:Rotenone; D009245:NADH Dehydrogenase