Single-molecule in vivo imaging of bacterial respiratory complexes indicates delocalized oxidative phosphorylation.
Biochim Biophys Acta
; 1837(6): 811-24, 2014 Jun.
Article
en En
| MEDLINE
| ID: mdl-24513194
ABSTRACT
Chemiosmotic energy coupling through oxidative phosphorylation (OXPHOS) is crucial to life, requiring coordinated enzymes whose membrane organization and dynamics are poorly understood. We quantitatively explore localization, stoichiometry, and dynamics of key OXPHOS complexes, functionally fluorescent protein-tagged, in Escherichia coli using low-angle fluorescence and superresolution microscopy, applying single-molecule analysis and novel nanoscale co-localization measurements. Mobile 100-200nm membrane domains containing tens to hundreds of complexes are indicated. Central to our results is that domains of different functional OXPHOS complexes do not co-localize, but ubiquinone diffusion in the membrane is rapid and long-range, consistent with a mobile carrier shuttling electrons between islands of different complexes. Our results categorically demonstrate that electron transport and proton circuitry in this model bacterium are spatially delocalized over the cell membrane, in stark contrast to mitochondrial bioenergetic supercomplexes. Different organisms use radically different strategies for OXPHOS membrane organization, likely depending on the stability of their environment.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
3_ND
Problema de salud:
3_neglected_diseases
/
3_zoonosis
Asunto principal:
Fosforilación Oxidativa
/
Transporte de Electrón
/
Escherichia coli
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
2014
Tipo del documento:
Article
País de afiliación:
Reino Unido