NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory chain. The immediate electron acceptor for the enzyme in this species is believed to be a menaquinone. Couples the redox reaction to proton translocation (for every two electrons transferred, four hydrogen ions are translocated across the cytoplasmic membrane), and thus conserves the redox energy in a proton gradient. a quinone + 5 H(+)(in) + NADH = a quinol + 4 H(+)(out) + NAD(+) Binds 1 [4Fe-4S] cluster. NDH-1 is composed of 14 different subunits. Subunits NuoB, C, D, E, F, and G constitute the peripheral sector of the complex (By similarity). Belongs to the complex I 20 kDa subunit family.