3s8f

1.8 A structure of ba3 cytochrome c oxidase from Thermus thermophilus in lipid environment

spinqualitylabelsall models 3s8f, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3s8f 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 1.8Å Ligands: CU, CUA, HEM, OLC, PER Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function COX1_THET8 Publication Abstract from PubMed The fundamental chemistry underpinning aerobic life on Earth involves reduction of dioxygen to water with concomitant proton translocation. This process is catalyzed by members of the heme-copper oxidase (HCO) superfamily. Despite the availability of crystal structures for all types of HCO, the mode of action for this enzyme is not understood at the atomic level, namely how vectorial H(+) and e(-) transport are coupled. Toward addressing this problem, we report wild type and A120F mutant structures of the ba(3)-type cytochrome c oxidase from Thermus thermophilus at 1.8 A resolution. The enzyme has been crystallized from the lipidic cubic phase, which mimics the biological membrane environment. The structures reveal 20 ordered lipid molecules that occupy binding sites on the protein surface or mediate crystal packing interfaces. The interior of the protein encloses 53 water molecules, including 3 trapped in the designated K-path of proton transfer and 8 in a cluster seen also in A-type enzymes that likely functions in egress of product water and proton translocation. The hydrophobic O(2)-uptake channel, connecting the active site to the lipid bilayer, contains a single water molecule nearest the Cu(B) atom but otherwise exhibits no residual electron density. The active site contains strong electron density for a pair of bonded atoms bridging the heme Fe(a3) and Cu(B) atoms that is best modeled as peroxide. The structure of ba(3)-oxidase reveals new information about the positioning of the enzyme within the membrane and the nature of its interactions with lipid molecules. The atomic resolution details provide insight into the mechanisms of electron transfer, oxygen diffusion into the active site, reduction of oxygen to water, and pumping of protons across the membrane. The development of a robust system for production of ba(3)-oxidase crystals diffracting to high resolution, together with an established expression system for generating mutants, opens the door for systematic structure-function studies. High resolution structure of the ba3 cytochrome c oxidase from Thermus thermophilus in a lipidic environment.,Tiefenbrunn T, Liu W, Chen Y, Katritch V, Stout CD, Fee JA, Cherezov V PLoS One. 2011;6(7):e22348. Epub 2011 Jul 21. PMID:21814577 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome c oxidase 3D structures

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