Critical roles of the Cu_B site in efficient proton pumping as revealed by crystal structures of mammalian cytochrome c oxidase catalytic intermediates.

ABSTRACT: Mammalian cytochrome c oxidase (CcO) reduces O₂ to water in a bimetallic site including Fe_a3 and Cu_B giving intermediate molecules, termed A-, P-, F-, O-, E-, and R-forms. From the P-form on, each reaction step is driven by single-electron donations from cytochrome c coupled with the pumping of a single proton through the H-pathway, a proton-conducting pathway composed of a hydrogen-bond network and a water channel. The proton-gradient formed is utilized for ATP production by F-ATPase. For elucidation of the proton pumping mechanism, crystal structural determination of these intermediate forms is necessary. Here we report X-ray crystallographic analysis at ∼1.8 Å resolution of fully reduced CcO crystals treated with O₂ for three different time pe

SUBMITTER: Shimada A 

PROVIDER: S-EPMC8390519 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature