Active NDH-1 complexes from the cyanobacterium Synechocystis sp. strain PCC 6803.

We identified eight bands by staining native gels for NADPH-nitroblue tetrazolium oxidoreductase activity after electrophoresis of n-dodecyl-beta-d-maltoside-treated membranes of Synechocystis sp. strain PCC 6803. Among them, bands A, C, D and E were attributed to the activity of NADPH dehydrogenase (NDH-1). Band A is a highly active supercomplex of NDH-1 (about 1,000 kDa) that was absent in the DeltandhD1/D2 mutant and was suppressed under low CO(2). Band C was induced under low CO(2) or in the DeltandhD1/D2 mutant and was converted to bands D and E. Bands A and C appear to be an NDH-1L dimer and NDH-1M, respectively, with subunits essential for the activity.