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-Structure paper
Title | Cryo-EM structures of intermediates suggest an alternative catalytic reaction cycle for cytochrome c oxidase. |
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Journal, issue, pages | Nat Commun, Vol. 12, Issue 1, Page 6903, Year 2021 |
Publish date | Nov 25, 2021 |
![]() | F Kolbe / S Safarian / Ż Piórek / S Welsch / H Müller / H Michel / ![]() |
PubMed Abstract | Cytochrome c oxidases are among the most important and fundamental enzymes of life. Integrated into membranes they use four electrons from cytochrome c molecules to reduce molecular oxygen (dioxygen) ...Cytochrome c oxidases are among the most important and fundamental enzymes of life. Integrated into membranes they use four electrons from cytochrome c molecules to reduce molecular oxygen (dioxygen) to water. Their catalytic cycle has been considered to start with the oxidized form. Subsequent electron transfers lead to the E-state, the R-state (which binds oxygen), the P-state (with an already split dioxygen bond), the F-state and the O-state again. Here, we determined structures of up to 1.9 Å resolution of these intermediates by single particle cryo-EM. Our results suggest that in the O-state the active site contains a peroxide dianion and in the P-state possibly an intact dioxygen molecule, the F-state may contain a superoxide anion. Thus, the enzyme's catalytic cycle may have to be turned by 180 degrees. |
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Methods | EM (single particle) |
Resolution | 2.4 - 2.66 Å |
Structure data | EMDB-11921, PDB-7ate: EMDB-11922, PDB-7atn: EMDB-11924, PDB-7au3: EMDB-11925, PDB-7au6: |
Chemicals | ![]() ChemComp-MN: ![]() ChemComp-HEA: ![]() ChemComp-CU: ![]() ChemComp-CA: ![]() ChemComp-PEO: ![]() ChemComp-CUA: ![]() ChemComp-PC1: ![]() ChemComp-PGV: ![]() ChemComp-HOH: ![]() ChemComp-O: ![]() ChemComp-2FK: ![]() ChemComp-OXY: |
Source |
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![]() | MEMBRANE PROTEIN / Terminal oxidase Cytochrome c oxidase aa3 oxidase |