Electrogenic steps during electron transfer via the cytochrome bc1 complex of Rhodobacter sphaeroides chromatophores

The results of the flash-induced electrometrical investigation on the functioning of the photosynthetic bacterial cytochrome bc1 complex are discussed. The data suggest possible arrangement of redox centers in the bc1 complex and propose that the total electrogenesis within the bc1 complex includes: (i) electron transfer between the low- and the high-potential cytochrome b hemes, (ii) proton binding by doubly reduced Q2- at ubiquinone reducing center 'C', and (iii) proton release on oxidation of QH2 at ubiquinol-oxidizing center 'Z'.