Crystallographic cyanide-probing for cytochrome c oxidase reveals structural bases suggesting that a putative proton transfer H-pathway pumps protons.

ABSTRACT: Cytochrome c oxidase (CcO) reduces O₂ in the O₂-reduction site by sequential four-electron donations through the low-potential metal sites (Cu_A and Fe_a). Redox-coupled X-ray crystal structural changes have been identified at five distinct sites including Asp⁵¹, Arg⁴³⁸, Glu¹⁹⁸, the hydroxyfarnesyl ethyl group of heme a, and Ser³⁸², respectively. These sites interact with the putative proton-pumping H-pathway. However, the metal sites responsible for each structural change have not been identified, since these changes were detected as structural differences between the fully reduced and fully oxidized CcOs. Thus, the roles of these structural changes in the CcO function are yet to be revealed. X-ray cryst

SUBMITTER: Shimada A 

PROVIDER: S-EPMC10598403 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature