| Literature DB >> 30808749 |
Izumi Ishigami1, Ariel Lewis-Ballester1, Austin Echelmeier2,3, Gerrit Brehm2,3,4, Nadia A Zatsepin2,5, Thomas D Grant6, Jesse D Coe2,3, Stella Lisova2,3, Garrett Nelson2,5, Shangji Zhang2,3, Zachary F Dobson2,3, Sébastien Boutet7, Raymond G Sierra7, Alexander Batyuk7, Petra Fromme2,3, Raimund Fromme2,3, John C H Spence2,5, Alexandra Ros2,3, Syun-Ru Yeh1, Denis L Rousseau8.
Abstract
Cytochrome c oxidase (CcO) reduces dioxygen to water and harnesses the chemical energy to drive proton translocation across the inner mitochondrial membrane by an unresolved mechanism. By using time-resolved serial femtosecond crystallography, we identified a key oxygen intermediate of bovine CcO. It is assigned to the PR-intermediate, which is characterized by specific redox states of the metal centers and a distinct protein conformation. The heme a 3 iron atom is in a ferryl (Fe4+ = O2-) configuration, and heme a and CuB are oxidized while CuA is reduced. A Helix-X segment is poised in an open conformational state; the heme a farnesyl sidechain is H-bonded to S382, and loop-I-II adopts a distinct structure. These data offer insights into the mechanism by which the oxygen chemistry is coupled to unidirectional proton translocation.Entities:
Keywords: X-ray free electron laser; bioenergetics; catalytic intermediates; complex IV; crystallography
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Year: 2019 PMID： 30808749 PMCID： PMC6397517 DOI： 10.1073/pnas.1814526116
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205