Experimental evidence for proton motive force-dependent catalysis by the diheme-containing succinate:menaquinone oxidoreductase from the Gram-positive bacterium Bacillus licheniformis

The purification, reconstitution into proteoliposomes and functional characterization of the diheme-containing succinate:menaquinone reductase from the Gram-positive bacterium Bacillus licheniformis is described. The design, synthesis and characterization of quinones with finely tuned oxidation/reduction potentials have provided evidence for [DELTA]p (transmembrane electrochemical proton potential)-dependent catalysis of succinate oxidation by quinone as well as for [DELTA]p generation upon catalysis of fumarate reduction by quinol.