1996/05/24 by Tomitake Tsukihara, Hiroshi Aoyama, Eiki Yamashita +6 · 5 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Neuroscience · #Amino acid #Biochemistry #Chemistry #Crystallography #Cytochrome #Cytochrome c oxidase #Dimer #Enzyme #Heme #Heme A #Histidine #Hydrogen bond #Imidazole #Ligand (biochemistry) #Mitochondrial Function and Pathology #Molecule #Organic chemistry #Photoreceptor and optogenetics research #Photosynthetic Processes and Mechanisms #Protein subunit #Receptor #Stereochemistry
paper · doi:10.1126/science.272.5265.1136
openalex publication_date 1996/05/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The crystal structure of bovine heart cytochrome c oxidase at 2.8 A resolution with an R value of 19.9 percent reveals 13 subunits, each different from the other, five phosphatidyl ethanolamines, three phosphatidyl glycerols and two cholates, two hemes A, and three copper, one magnesium, and one zinc. Of 3606 amino acid residues in the dimer, 3560 have been converged to a reasonable structure by refinement. A hydrogen-bonded system, including a propionate of a heme A (heme a), part of peptide backbone, and an imidazole ligand of CuA, could provide an electron transfer pathway between CuA and heme a. Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains. Possible channels for chemical protons to produce H2O, for removing the produced water, and for O2, respectively, were identified.