NDH-1 shuttles electrons from an unknown electron donor, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory and/or the photosynthetic chain. The immediate electron acceptor for the enzyme in this species is believed to be plastoquinone. Couples the redox reaction to proton translocation, and thus conserves the redox energy in a proton gradient. Cyanobacterial NDH-1 also plays a role in inorganic carbon-concentration. a plastoquinone + (n+1) H(+)(in) + NADH = a plastoquinol + n H(+)(out) + NAD(+) a plastoquinone + (n+1) H(+)(in) + NADPH = a plastoquinol + n H(+)(out) + NADP(+) NDH-1 can be composed of about 15 different subunits; different subcomplexes with different compositions have been identified which probably have different functions. Belongs to the complex I NdhM subunit family.