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Bovine Heart Cytochrome C Oxidase (bovine + heart_cytochrome_c_oxidase)
Selected AbstractsIntermonomer interactions in dimer of bovine heart cytochrome c oxidaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2001Soo Jae Lee The X-ray structure of bovine heart cytochrome c oxidase solved for orthorhombic crystals showed a dimeric structure stabilized by four subunit,subunit contacts, namely, subunit Vb,subunit Vb on the matrix side, subunit I,subunit VIa, subunit VIa,subunit I in the transmembrane region and subunit VIb,subunit VIb on the intermembrane side. The same intermonomer contacts as in the orthorhombic crystals were observed in both hexagonal and tetragonal crystals, the X-ray structures of which were determined by the molecular-replacement method. These results suggest that the dimeric structure also exists under physiological conditions. These contacts, especially the subunit IVa,subunit I contact, in which the N-terminal portion of subunit IVa is placed on the surface of subunit I near the dioxygen-reduction site, indicate that the function of the bovine heart enzyme is likely to be controlled by perturbation of the monomer,monomer association. [source] X-ray structure of azide-bound fully oxidized cytochrome c oxidase from bovine heart at 2.9,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2000Ming Jie Fei Two azide ions were identified, one between the Fe and Cu atoms in the O2 -reduction site and the other at the transmembrane surface of the enzyme, in the crystal structure of the azide-bound form of bovine heart cytochrome c oxidase at 2.9,Å resolution. Two geometries, a ,-1,3 type geometry between the Fe and Cu atoms and a terminal geometry on the Fe atom, are equally possible for an azide ion in the O2 -reduction site. The other azide molecule was hydrogen bonded to an amide group of an asparagine and a hydroxyl group of tyrosine in a ,-1,1 type geometry. The antisymmetric infrared bands arising from these azide ions, which show essentially identical intensity [Yoshikawa & Caughey (1992), J. Biol. Chem.267, 9757,9766], strongly suggest terminal binding of the azide to Fe. The electron density of all three imidazole ligands to CuB was clearly seen in the electron-density map of the azide-bound form of bovine heart enzyme, in contrast to the crystal structure of the azide-bound form of the bacterial enzyme [Iwata et al. (1995), Nature (London), 376, 660,669], which lacks one of the three imidazole ligands to CuB. [source] X-ray structure of the NO-bound CuB in bovine cytochrome c oxidaseACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Kazuhiro Ohta The X-ray crystallographic structure of nitric oxide-treated bovine heart cytochrome c oxidase (CcO) in the fully reduced state has been determined at 50,K under light illumination. In this structure, nitric oxide (NO) is bound to the CcO oxygen-reduction site, which consists of haem and a Cu atom (the haem a3,CuB site). Electron density for the NO molecule was observed close to CuB. The refined structure indicates that NO is bound to CuB in a side-on manner. [source] | ||||||||||