NQR complex catalyzes the reduction of ubiquinone-1 to ubiquinol by two successive reactions, coupled with the transport of Na(+) ions from the cytoplasm to the periplasm. The first step is catalyzed by NqrF, which accepts electrons from NADH and reduces ubiquinone-1 to ubisemiquinone by a one-electron transfer pathway. a ubiquinone + H(+) + n Na(+)(in) + NADH = a ubiquinol + n Na(+)(out) + NAD(+) Binds 1 [2Fe-2S] cluster. Composed of six subunits; NqrA, NqrB, NqrC, NqrD, NqrE and NqrF. Belongs to the NqrF family.