Conserved in situ arrangement of complex I and III2 in mitochondrial respiratory chain supercomplexes of mammals, yeast, and plants.
Proc Natl Acad Sci U S A
; 115(12): 3024-3029, 2018 03 20.
Article
em En
| MEDLINE
| ID: mdl-29519876
ABSTRACT
We used electron cryo-tomography and subtomogram averaging to investigate the structure of complex I and its supramolecular assemblies in the inner mitochondrial membrane of mammals, fungi, and plants. Tomographic volumes containing complex I were averaged at â¼4 nm resolution. Principal component analysis indicated that â¼60% of complex I formed a supercomplex with dimeric complex III, while â¼40% were not associated with other respiratory chain complexes. The mutual arrangement of complex I and III2 was essentially conserved in all supercomplexes investigated. In addition, up to two copies of monomeric complex IV were associated with the complex I1III2 assembly in bovine heart and the yeast Yarrowia lipolytica, but their positions varied. No complex IV was detected in the respiratory supercomplex of the plant Asparagus officinalis Instead, an â¼4.5-nm globular protein density was observed on the matrix side of the complex I membrane arm, which we assign to γ-carbonic anhydrase. Our results demonstrate that respiratory chain supercomplexes in situ have a conserved core of complex I and III2, but otherwise their stoichiometry and structure varies. The conserved features of supercomplex assemblies indicate an important role in respiratory electron transfer.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bovinos
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Complexo III da Cadeia de Transporte de Elétrons
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Yarrowia
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Asparagus
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Complexo I de Transporte de Elétrons
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article