Cyanobacteria contain a mitochondrial complex I-homologous NADH-dehydrogenase.
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.
Berger
S
S
Institut für Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität Düsseldorf, Germany.
Ellersiek
U
U
Steinmüller
K
K
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
D012402:Rotenone; D009245:NADH Dehydrogenase