Binding dynamics at the quinone reduction (Qi) site influence the equilibrium interactions of the iron sulfur protein and hydroquinone oxidation (Qo) site of the cytochrome bc1 complex.

ABSTRACT: Multiple instances of low-potential electron-transport pathway inhibitors that affect the structure of the cytochrome (cyt) bc(1) complex to varying degrees, ranging from changes in hydroquinone (QH(2)) oxidation and cyt c(1) reduction kinetics to proteolytic accessibility of the hinge region of the iron-sulfur-containing subunit (Fe/S protein), have been reported. However, no instance has been documented of any ensuing change on the environment(s) of the [2Fe-2S] cluster. In this work, this issue was addressed in detail by taking advantage of the increased spectral and spatial resolution obtainable with orientation-dependent electron paramagnetic resonance (EPR) spectroscopic analysis of ordered membrane preparations. For the first time, perturbation of the low-potential electron-transpor

SUBMITTER: Cooley JW 

PROVIDER: S-EPMC1360200 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature