NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory chain. 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 (By similarity). a quinone + 5 H(+)(in) + NADH = a quinol + 4 H(+)(out) + NAD(+) NDH-1 is composed of 14 different subunits. Subunits NuoB, C, D, E, F, and G constitute the peripheral sector of the complex. Belongs to the complex I 20 kDa subunit family. This protein lacks the conserved Cys in position 39; it is replaced by Arg. Thus this protein is probably unable to bind the 4Fe-4S cluster and may be non-functional.