Cyanobacterial NDH-1 complexes: Novel insights and remaining puzzles

Cyanobacterial NDH-1 complexes belong to a family of energy converting NAD(P)H:Quinone oxidoreductases that includes bacterial type-I NADH dehydrogenase and mitochondrial Complex I. Several distinct NDH-1 complexes may coexist in cyanobacterial cells and thus be responsible for a variety of functions including respiration, cyclic electron flow around PSI and CO2 uptake. The present review is focused on specific features that allow to regard the cyanobacterial NDH-1 complexes, together with NDH complexes from chloroplasts, as a separate sub-class of the Complex I family of enzymes. Here, we summarize our current knowledge about structure of functionally different NDH-1 complexes in cyanobacteria and consider implications for a functional mechanism. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts. (C) 2010 Elsevier B.V. All rights reserved.