Architecture and assembly dynamics of the essential mitochondrial chaperone complex TIM9·10·12.
Structure
; 29(9): 1065-1073.e4, 2021 09 02.
Article
em En
| MEDLINE
| ID: mdl-33974880
ABSTRACT
Tim chaperones transport membrane proteins to the two mitochondrial membranes. TIM9·10, a 70 kDa protein complex formed by 3 copies of Tim9 and Tim10, guides its clients across the aqueous compartment. The TIM9·10·12 complex is the anchor point at the inner-membrane insertase TIM22. The subunit composition of TIM9·10·12 remains debated. Joint NMR, small-angle X-ray scattering, and MD simulation data allow us to derive a structural model of the TIM9·10·12 assembly, with a 231 stoichiometry (Tim9Tim10Tim12). Both TIM9·10 and TIM9·10·12 hexamers are in a dynamic equilibrium with their constituent subunits, exchanging on a minutes timescale. NMR data establish that the subunits exhibit large conformational dynamics when the conserved cysteines of the CX3C-Xn-CX3C motifs are formed, short α helices are formed, and these are fully stabilized only upon formation of the mature hexameric chaperone. We propose that the continuous subunit exchange allows mitochondria to control their level of inter-membrane space chaperones.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Saccharomyces cerevisiae
/
Multimerização Proteica
/
Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial
Idioma:
En
Revista:
Structure
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
BIOTECNOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
França