8GBT

Time-resolve SFX structure of a photoproduct of carbon monoxide complex of bovine cytochrome c oxidase

Summary for 8GBT

• Entry DOI: 10.2210/pdb8gbt/pdb
• Descriptor: Cytochrome c oxidase subunit 1, Cytochrome c oxidase subunit 7A1, mitochondrial, Cytochrome c oxidase subunit 7B, mitochondrial, ... (30 entities in total)
• Functional Keywords: oxidative phosphorylation, electron transfer chain, bioenergetics, cytochrome c oxidase, serial femtosecond x-ray crystallography, membrane protein
• Biological source: Bos taurus (cattle); More
• Total number of polymer chains: 26
• Total formula weight: 443140.29

Authors

Ishigami, I.,Yeh, S.-R.,Rousseau, D.L. (deposition date: 2023-02-28, release date: 2023-09-20, Last modification date: 2023-11-01)

Primary citation

Ishigami, I.,Carbajo, S.,Zatsepin, N.,Hikita, M.,Conrad, C.E.,Nelson, G.,Coe, J.,Basu, S.,Grant, T.,Seaberg, M.H.,Sierra, R.G.,Hunter, M.S.,Fromme, P.,Fromme, R.,Rousseau, D.L.,Yeh, S.R.
Detection of a Geminate Photoproduct of Bovine Cytochrome c Oxidase by Time-Resolved Serial Femtosecond Crystallography.
J.Am.Chem.Soc., 145:22305-22309, 2023

PubMed Abstract: Cytochrome oxidase (CO) is a large membrane-bound hemeprotein that catalyzes the reduction of dioxygen to water. Unlike classical dioxygen binding hemeproteins with a heme group in their active sites, CO has a unique binuclear center (BNC) composed of a copper atom (Cu) and a heme iron, where O binds and is reduced to water. CO is a versatile O surrogate in ligand binding and escape reactions. Previous time-resolved spectroscopic studies of the CO complexes of bovine CO (bCO) revealed that photolyzing CO from the heme iron leads to a metastable intermediate (Cu-CO), where CO is bound to Cu, before it escapes out of the BNC. Here, with a pump-probe based time-resolved serial femtosecond X-ray crystallography, we detected a geminate photoproduct of the bCO-CO complex, where CO is dissociated from the heme iron and moved to a temporary binding site midway between the Cu and the heme iron, while the locations of the two metal centers and the conformation of Helix-X, housing the proximal histidine ligand of the heme iron, remain in the CO complex state. This new structure, combined with other reported structures of bCO, allows for a clearer definition of the ligand dissociation trajectory as well as the associated protein dynamics.

PubMed: 37695261
DOI: 10.1021/jacs.3c07803

Experimental method

X-RAY DIFFRACTION (2.8 Å)