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| == Function == | | == Function == |
| [https://www.uniprot.org/uniprot/COX1_BOVIN COX1_BOVIN] Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1-3 form the functional core of the enzyme complex. CO I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit 2 and heme A of subunit 1 to the bimetallic center formed by heme A3 and copper B. | | [https://www.uniprot.org/uniprot/COX1_BOVIN COX1_BOVIN] Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1-3 form the functional core of the enzyme complex. CO I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit 2 and heme A of subunit 1 to the bimetallic center formed by heme A3 and copper B. |
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| == Publication Abstract from PubMed ==
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| Cytochrome c oxidase (CcO) is an essential enzyme in mitochondrial and bacterial respiration. It catalyzes the four-electron reduction of molecular oxygen to water and harnesses the chemical energy to translocate four protons across biological membranes. The turnover of the CcO reaction involves an oxidative phase, in which the reduced enzyme (R) is oxidized to the metastable O(H) state, and a reductive phase, in which O(H) is reduced back to the R state. During each phase, two protons are translocated across the membrane. However, if O(H) is allowed to relax to the resting oxidized state (O), a redox equivalent to O(H), its subsequent reduction to R is incapable of driving proton translocation. Here, with resonance Raman spectroscopy and serial femtosecond X-ray crystallography (SFX), we show that the heme a(3) iron and Cu(B) in the active site of the O state, like those in the O(H) state, are coordinated by a hydroxide ion and a water molecule, respectively. However, Y244, critical for the oxygen reduction chemistry, is in the neutral protonated form, which distinguishes O from O(H), where Y244 is in the deprotonated tyrosinate form. These structural characteristics of O provide insights into the proton translocation mechanism of CcO.
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| Structural insights into functional properties of the oxidized form of cytochrome c oxidase.,Ishigami I, Sierra RG, Su Z, Peck A, Wang C, Poitevin F, Lisova S, Hayes B, Moss FR 3rd, Boutet S, Sublett RE, Yoon CH, Yeh SR, Rousseau DL Nat Commun. 2023 Sep 16;14(1):5752. doi: 10.1038/s41467-023-41533-x. PMID:37717031<ref>PMID:37717031</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 8gcq" style="background-color:#fffaf0;"></div>
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| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
