Component of the respiratory Qrc complex, that catalyzes the reduction of the menaquinone pool using electrons transferred from the reduced periplasmic cytochrome c3, and which is probably involved in sulfate respiration. Is likely essential for growth on H(2) or formate since the periplasmic hydrogenases and/or formate dehydrogenases act as primary electron donors for the Qrc complex. The QrcD subunit anchors the protein complex to the membrane and likely interacts with the quinone pool. The Qrc complex is composed of four subunits: QrcA, QrcB, QrcC and QrcD (PubMed:20498375). Can form a supercomplex with the [NiFe] hydrogenase HynA1 and the tetraheme Type I cytochrome c3 TpIc(3), its physiological electron donors (PubMed:21651911). Belongs to the NrfD family.