3S8F

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

3S8F の概要

• エントリーDOI: 10.2210/pdb3s8f/pdb
• 分子名称: Cytochrome c oxidase subunit 1, Cytochrome c oxidase subunit 2, Cytochrome c oxidase polypeptide 2A, ... (10 entities in total)
• 機能のキーワード: complex iv, respiratory chain, lipid cubic phase, monoolein, peroxide, electron transport, proton pump, oxidoreductase, membrane
• 由来する生物種: Thermus thermophilus; 詳細
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: Q5SJ79; Cell membrane; Single-pass membrane protein: Q5SJ80 P82543
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 93355.76

構造登録者

Tiefenbrunn, T.,Liu, W.,Chen, Y.,Katritch, V.,Stout, C.D.,Fee, J.A.,Cherezov, V. (登録日: 2011-05-27, 公開日: 2011-08-03, 最終更新日: 2024-02-28)

主引用文献

Tiefenbrunn, T.,Liu, W.,Chen, Y.,Katritch, V.,Stout, C.D.,Fee, J.A.,Cherezov, V.
High resolution structure of the ba3 cytochrome c oxidase from Thermus thermophilus in a lipidic environment.
Plos One, 6:e22348-e22348, 2011

PubMed Abstract: 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 Å 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.

PubMed: 21814577
DOI: 10.1371/journal.pone.0022348

実験手法

X-RAY DIFFRACTION (1.8 Å)