Inter-membrane association of the Sec and BAM translocons for bacterial outer-membrane biogenesis.
Elife
; 92020 11 04.
Article
en En
| MEDLINE
| ID: mdl-33146611
ABSTRACT
The outer-membrane of Gram-negative bacteria is critical for surface adhesion, pathogenicity, antibiotic resistance and survival. The major constituent - hydrophobic ß-barrel Outer-Membrane Proteins (OMPs) - are first secreted across the inner-membrane through the Sec-translocon for delivery to periplasmic chaperones, for example SurA, which prevent aggregation. OMPs are then offloaded to the ß-Barrel Assembly Machinery (BAM) in the outer-membrane for insertion and folding. We show the Holo-TransLocon (HTL) - an assembly of the protein-channel core-complex SecYEG, the ancillary sub-complex SecDF, and the membrane 'insertase' YidC - contacts BAM through periplasmic domains of SecDF and YidC, ensuring efficient OMP maturation. Furthermore, the proton-motive force (PMF) across the inner-membrane acts at distinct stages of protein secretion (1) SecA-driven translocation through SecYEG and (2) communication of conformational changes via SecDF across the periplasm to BAM. The latter presumably drives efficient passage of OMPs. These interactions provide insights of inter-membrane organisation and communication, the importance of which is becoming increasingly apparent.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de la Membrana Bacteriana Externa
/
Regulación Bacteriana de la Expresión Génica
/
Escherichia coli
/
Sistemas de Secreción Bacterianos
Tipo de estudio:
Risk_factors_studies
Idioma:
En
Revista:
Elife
Año:
2020
Tipo del documento:
Article
País de afiliación:
Reino Unido