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The Unusual Homodimer of a Heme‐Copper Terminal Oxidase Allows Itself to Utilize Two Electron Donors
Author(s) -
Zhu Guoliang,
Zeng Hui,
Zhang Shuangbo,
Juli Jana,
Tai Linhua,
Zhang Danyang,
Pang Xiaoyun,
Zhang Yan,
Lam Sin Man,
Zhu Yun,
Peng Guohong,
Michel Hartmut,
Sun Fei
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202016785
Subject(s) - aquifex aeolicus , cytochrome c oxidase , heme a , chemistry , oxidase test , electron transfer , heme , protein subunit , electron transport complex iv , cytochrome b , coenzyme q – cytochrome c reductase , electron transport chain , cytochrome c1 , cytochrome , biochemistry , enzyme , cytochrome c , mitochondrion , photochemistry , gene , mitochondrial dna , escherichia coli
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.