Structural Changes and Proton Transfer in Cytochrome c Oxidase.

ABSTRACT: In cytochrome c oxidase electron transfer from cytochrome c to O2 is linked to transmembrane proton pumping, which contributes to maintaining a proton electrochemical gradient across the membrane. The mechanism by which cytochrome c oxidase couples the exergonic electron transfer to the endergonic proton translocation is not known, but it presumably involves local structural changes that control the alternating proton access to the two sides of the membrane. Such redox-induced structural changes have been observed in X-ray crystallographic studies at residues 423-425 (in the R. sphaeroides oxidase), located near heme a. The aim of the present study is to investigate the functional effects of these structural changes on reaction steps associated with proton pumping. Residue Ser425 was modif

SUBMITTER: Vilhjalmsdottir J 

PROVIDER: S-EPMC4550891 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature