A peroxide bridge between Fe and Cu ions in the O2 reduction site of fully oxidized cytochrome c oxidase could suppress the proton pump.

ABSTRACT: The fully oxidized form of cytochrome c oxidase, immediately after complete oxidation of the fully reduced form, pumps protons upon each of the initial 2 single-electron reduction steps, whereas protons are not pumped during single-electron reduction of the fully oxidized "as-isolated" form (the fully oxidized form without any reduction/oxidation treatment) [Bloch D, et al. (2004) The catalytic cycle of cytochrome c oxidase is not the sum of its two halves. Proc Natl Acad Sci USA 101:529-533]. For identification of structural differences causing the remarkable functional difference between these 2 distinct fully oxidized forms, the X-ray structure of the fully oxidized as-isolated bovine heart cytochrome c oxidase was determined at 1.95-A resolution by limiting the X-ray dose for each shot

SUBMITTER: Aoyama H 

PROVIDER: S-EPMC2650126 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature