Na + -NQR is a unique energy-transducing complex, widely distributed among marine and pathogenic bacteria. It converts the energy from the oxidation of NADH and the reduction of quinone into an electrochemical Na + -gradient that can provide energy for the cell. Na + -NQR is not homologous to any other respiratory protein but is closely related to the RNF complex. In this review we propose that sodium pumping in Na + -NQR is coupled to the redox reactions by a novel mechanism, which operates at multiple sites, is indirect and mediated by conformational changes of the protein. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).