[1] In 1979, Trumpower's team isolated the "oxidation factor" from bovine mitochondria and showed it was a reconstitutively-active form of the Rieske iron-sulfur protein.

They have since been found in plants, animals, and bacteria with widely ranging electron reduction potentials from -150 to +400 mV.

It catalyses the oxidation-reduction reaction of the mobile components ubiquinol and cytochrome c, contributing to an electrochemical potential difference across the mitochondrial inner or bacterial membrane, which is linked to ATP synthesis.

[4][7] The reduction of the Rieske center increases the affinity of the subunit by several orders of magnitude, stabilizing the semiquinone radical at the Q(P) site.

The overall fold, comprising two subdomains, is dominated by antiparallel β-structure and contains variable numbers of α-helices.