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Insight into mammalian respiratory complexes defines the role of allosteric protein interactions in their proton-motive activity. In cytochrome c oxidase (CxIV) conformational change of subunit I, caused by O 2 binding to heme a 3 2+-Cu B + and reduction, and stereochemical transitions coupled to oxidation/reduction of heme a and Cu A , combined with electrostatic effects, determine the proton pumping activity. In ubiquinone-cytochrome c oxidoreductase (CxIII) conformational movement of Fe–S protein between cytochromes b and c 1 is the key element of the proton-motive activity. In NADH-ubiquinone oxidoreductase (CxI) ubiquinone binding and reduction result in conformational changes of subunits in the quinone reaction structure which initiate proton pumping. • The role of allosteric protein interactions in mammalian respiratory complexes. • Conformational changes and electrostatic effects determine proton pumping in CxIV. • Role of conformational movement of Fe–S protein in proton-motive activity of CxIII. • Redox coupled subunits conformational changes initiate proton pumping in CxI. [ABSTRACT FROM AUTHOR]