Redox-Coupled Crystal Structural Changes in Bovine Heart Cytochrome c Oxidase

• DOI: 10.1126/science.280.5370.1723
• Publication Date: 2002-07-27T09:49:42Z
• Authors: Shinya Yoshikawa; Kyoko Shinzawa-Itoh; Ryosuke Nakashima; Rieko Yaono; Eiki Yamashita; Noriko Inoue; Min Yao; Ming Jie Fei; Clare Peters Libeu; Tsunehiro Mizushima; Hiroshi Yamaguchi; Takashi Tomizaki; Tomitake Tsukihara
• Keywords: Imidazole

Crystal structures of bovine heart cytochrome c oxidase in the fully oxidized, reduced, azide-bound, and carbon monoxide–bound states were determined at 2.30, 2.35, 2.9, 2.8 angstrom resolution, respectively. An aspartate residue apart from O 2 reduction site exchanges its effective accessibility to matrix aqueous phase for one cytosolic concomitantly with a significant decrease pK carboxyl group, on metal sites. The movement indicates as proton pumping site. A tyrosine acidified by covalently linked imidazole nitrogen is possible donor enzyme.