Protonmotive pathways and mechanisms in the cytochrome bc1 complex

AbstractThe cytochrome bc1 complex catalyzes electron transfer from ubiquinol to cytochrome c by a protonmotive Q cycle mechanism in which electron transfer is linked to proton translocation across the inner mitochondrial membrane. In the Q cycle mechanism proton translocation is the net result of topographically segregated reduction of quinone and reoxidation of quinol on opposite sides of the membrane, with protons being carried across the membrane as hydrogens on the quinol. The linkage of proton chemistry to electron transfer during quinol oxidation and quinone reduction requires pathways for moving protons to and from the aqueous phase and the hydrophobic environment in which the quinol and quinone redox reactions occur. Crystal structures of the mitochondrial cytochrome bc1 complexes in various conformations allow insight into possible proton conduction pathways. In this review we discuss pathways for proton conduction linked to ubiquinone redox reactions with particular reference to recently determined structures of the yeast bc1 complex

Investigating the on-site of the cytochrome bc1 complex in S. Cerevisiae with mutants resistant to Ilicicolin H, a novel on site inhibitor

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Combining inhibitor resistance-conferring mutations in cytochrome b creates conditional synthetic lethality in Saccharomyces cerevisiae.

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