EMD-13976

Single-particle
2.8 Å
EMD-13976 Deposition: 13/12/2021
Map released: 18/05/2022
Last modified: 09/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-13976

Cytochrome bcc-aa3 supercomplex (respiratory supercomplex III2/IV2) from Corynebacterium glutamicum (stigmatellin and azide bound)

EMD-13976

Single-particle
2.8 Å
EMD-13976 Deposition: 13/12/2021
Map released: 18/05/2022
Last modified: 09/10/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Corynebacterium glutamicum ATCC 13032
Sample: cytochrome bcc-aa3 supercomplex
Fitted models: 7qhm (Avg. Q-score: 0.567)

Deposition Authors: Kao W-C, Hunte C
Structural basis for safe and efficient energy conversion in a respiratory supercomplex.
PUBMED: 35087070
DOI: doi:10.1038/s41467-022-28179-x
ISSN: 2041-1723
Abstract:
Proton-translocating respiratory complexes assemble into supercomplexes that are proposed to increase the efficiency of energy conversion and limit the production of harmful reactive oxygen species during aerobic cellular respiration. Cytochrome bc complexes and cytochrome aa3 oxidases are major drivers of the proton motive force that fuels ATP generation via respiration, but how wasteful electron- and proton transfer is controlled to enhance safety and efficiency in the context of supercomplexes is not known. Here, we address this question with the 2.8 Å resolution cryo-EM structure of the cytochrome bcc-aa3 (III2-IV2) supercomplex from the actinobacterium Corynebacterium glutamicum. Menaquinone, substrate mimics, lycopene, an unexpected Qc site, dioxygen, proton transfer routes, and conformational states of key protonable residues are resolved. Our results show how safe and efficient energy conversion is achieved in a respiratory supercomplex through controlled electron and proton transfer. The structure may guide the rational design of drugs against actinobacteria that cause diphtheria and tuberculosis.