3bvd

Structure of Surface-engineered Cytochrome ba3 Oxidase from Thermus thermophilus under Xenon Pressure, 100psi 5min

spinqualitylabelsall models 3bvd, resolution 3.37Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3bvd is a 3 chain structure with sequence from Thermus thermophilus HB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.37Å Ligands: CU, CUA, HEM, XE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function COX1_THET8 Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Cytochrome ba 3 is a cytochrome c oxidase from the plasma membrane of Thermus thermophilus and is the preferred terminal enzyme of cellular respiration at low dioxygen tensions. Using cytochrome ba 3 crystals pressurized at varying conditions under Xe or Kr gas, and X-ray data for six crystals, we identify the relative affinities of Xe and Kr atoms for as many as seven distinct binding sites. These sites track a continuous, Y-shaped channel, 18-20 A in length, lined by hydrophobic residues, which leads from the surface of the protein where two entrance holes, representing the top of the Y, connect the bilayer to the a 3-Cu B center at the base of the Y. Considering the increased affinity of O 2 for hydrophobic environments, the hydrophobic nature of the channel, its orientation within the bilayer, its connection to the active site, its uniform diameter, its virtually complete occupation by Xe, and its isomorphous presence in the native enzyme, we infer that the channel is a diffusion pathway for O 2 into the dinuclear center of cytochrome ba 3. These observations provide a basis for analyzing similar channels in other oxidases of known structure, and these structures are discussed in terms of mechanisms of O 2 transport in biological systems, details of CO binding to and egress from the dinuclear center, the bifurcation of the oxygen-in and water-out pathways, and the possible role of the oxygen channel in aerobic thermophily. Crystallographic Studies of Xe and Kr Binding within the Large Internal Cavity of Cytochrome ba3 from Thermus thermophilus: Structural Analysis and Role of Oxygen Transport Channels in the Heme-Cu Oxidases(,).,Luna VM, Chen Y, Fee JA, Stout CD Biochemistry. 2008 Apr 22;47(16):4657-65. Epub 2008 Apr 1. PMID:18376849 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome c oxidase 3D structures

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