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A 3.3 Å‐Resolution Structure of Hyperthermophilic Respiratory Complex III Reveals the Mechanism of Its Thermal Stability
Author(s) -
Zhu Guoliang,
Zeng Hui,
Zhang Shuangbo,
Juli Jana,
Pang Xiaoyun,
Hoffmann Jan,
Zhang Yan,
Morgner Nina,
Zhu Yun,
Peng Guohong,
Michel Hartmut,
Sun Fei
Publication year - 2020
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.201911554
Subject(s) - thermophile , aquifex aeolicus , cytochrome c , cytochrome , transmembrane protein , crystallography , bacteria , chemistry , helix (gastropod) , biophysics , transmembrane domain , stereochemistry , membrane , biochemistry , biology , escherichia coli , mitochondrion , receptor , enzyme , ecology , genetics , snail , gene
Respiratory chain complexes convert energy by coupling electron flow to transmembrane proton translocation. Owing to a lack of atomic structures of cytochrome bc 1 complex (Complex III) from thermophilic bacteria, little is known about the adaptations of this macromolecular machine to hyperthermophilic environments. In this study, we purified the cytochrome bc 1 complex of Aquifex aeolicus , one of the most extreme thermophilic bacteria known, and determined its structure with and without an inhibitor at 3.3 Å resolution. Several residues unique for thermophilic bacteria were detected that provide additional stabilization for the structure. An extra transmembrane helix at the N‐terminus of cyt. c 1 was found to greatly enhance the interaction between cyt. b and cyt. c 1 , and to bind a phospholipid molecule to stabilize the complex in the membrane. These results provide the structural basis for the hyperstability of the cytochrome bc 1 complex in an extreme thermal environment.