Bovine cytochrome c oxidase structures enable O2 reduction with minimization of reactive oxygens and provide a proton-pumping gate.

ABSTRACT: The O(2) reduction site of cytochrome c oxidase (CcO), comprising iron (Fe(a3)) and copper (Cu(B)) ions, is probed by x-ray structural analyses of CO, NO, and CN(-) derivatives to investigate the mechanism of the complete reduction of O(2). Formation of the derivative contributes to the trigonal planar coordination of and displaces one of its three coordinated imidazole groups while a water molecule becomes hydrogen bonded to both the CN(-) ligand and the hydroxyl group of Tyr244. When O(2) is bound to Fe2+a3 , it is negatively polarized (O2- ), and expected to induce the same structural change induced by CN(-). This structural change allows to receive three electron equivalents nonsequentially from Cu1B+, Fe3+a3, and Tyr-OH, providing complete reduction of O(2) with minimization of produc

SUBMITTER: Muramoto K 

PROVIDER: S-EPMC2867921 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature