The Unusual Homodimer of a Heme-Copper Terminal Oxidase Allows Itself to Utilize Two Electron Donors
| Autor: | Xiaoyun Pang, Jana Juli, Fei Sun, Linhua Tai, Hui Zeng, Hartmut Michel, Guoliang Zhu, Guohong Peng, Shuangbo Zhang, Yan Zhang, Yun Zhu, Sin Man Lam, Danyang Zhang |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Ubiquinol
Stereochemistry naphthoquinone Electrons Heme 010402 general chemistry 01 natural sciences enzyme catalysis Catalysis Electron Transport Complex IV chemistry.chemical_compound Protein structure cytochrome c oxidase Cytochrome c oxidase Protein Structure Quaternary Research Articles chemistry.chemical_classification Aquifex aeolicus Oxidase test Binding Sites dimerization biology 010405 organic chemistry Cytochrome c Cryoelectron Microscopy General Chemistry General Medicine biology.organism_classification 0104 chemical sciences Aquifex Protein Subunits Enzyme chemistry Enzyme Catalysis | Hot Paper protein structures biology.protein Oxidation-Reduction Naphthoquinones Research Article |
| Zdroj: | Angewandte Chemie (International Ed. in English) |
| ISSN: | 1521-3773 |
| Popis: | The heme‐copper oxidase superfamily comprises cytochrome c and ubiquinol oxidases. These enzymes catalyze the transfer of electrons from different electron donors onto molecular oxygen. A B‐family cytochrome c oxidase from the hyperthermophilic bacterium Aquifex aeolicus was discovered previously to be able to use both cytochrome c and naphthoquinol as electron donors. Its molecular mechanism as well as the evolutionary significance are yet unknown. Here we solved its 3.4 Å resolution electron cryo‐microscopic structure and discovered a novel dimeric structure mediated by subunit I (CoxA2) that would be essential for naphthoquinol binding and oxidation. The unique structural features in both proton and oxygen pathways suggest an evolutionary adaptation of this oxidase to its hyperthermophilic environment. Our results add a new conceptual understanding of structural variation of cytochrome c oxidases in different species. The 3.4 Å structure of cytochrome c oxidase from the hyperthermophilic bacterium Aquifex aeolicus (AaCcO) has been solved. The molecular mechanism that AaCcO uses involves both cytochrome c and quinol as electron donors through the native quinol molecules (NQs) bound at the dimeric interface. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text