Temperature-dependent structural transition following X-ray-induced metal center reduction in oxidized cytochrome c oxidase.

ABSTRACT: Cytochrome c oxidase (CcO) is the terminal enzyme in the electron transfer chain in the inner membrane of mitochondria. It contains four metal redox centers, two of which, Cu_B and heme a₃, form the binuclear center (BNC), where dioxygen is reduced to water. Crystal structures of CcO in various forms have been reported, from which ligand-binding states of the BNC and conformations of the protein matrix surrounding it have been deduced to elucidate the mechanism by which the oxygen reduction chemistry is coupled to proton translocation. However, metal centers in proteins can be susceptible to X-ray-induced radiation damage, raising questions about the reliability of conclusions drawn from these studies. Here, we used microspectroscopy-coupled X-ray crystallography to in

SUBMITTER: Ishigami I 

PROVIDER: S-EPMC8971940 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature