Controlling membrane barrier during bacterial type-III protein secretion
GUSE, Alina
Humboldt-Universität zu Berlin = Humboldt University of Berlin = Université Humboldt de Berlin [HU Berlin]
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Humboldt-Universität zu Berlin = Humboldt University of Berlin = Université Humboldt de Berlin [HU Berlin]
GUSE, Alina
Humboldt-Universität zu Berlin = Humboldt University of Berlin = Université Humboldt de Berlin [HU Berlin]
< Leer menos
Humboldt-Universität zu Berlin = Humboldt University of Berlin = Université Humboldt de Berlin [HU Berlin]
Idioma
EN
Document de travail - Pré-publication
Resumen en inglés
Type-III secretion systems (T3SSs) of the bacterial flagellum and the evolutionarily related injectisome are capable of translocating proteins with a remarkable speed of several thousand amino acids per second. Here, we ...Leer más >
Type-III secretion systems (T3SSs) of the bacterial flagellum and the evolutionarily related injectisome are capable of translocating proteins with a remarkable speed of several thousand amino acids per second. Here, we investigated how T3SSs are able to transport proteins at such a high rate while preventing the leakage of small molecules. Our mutational and evolutionary analyses demonstrate that an ensemble of conserved methionine residues at the cytoplasmic side of the T3SS channel create a deformable gasket (M-gasket) around fast-moving substrates undergoing export. The unique physicochemical features of the M-gasket are crucial to preserve the membrane barrier, to accommodate local conformational changes during active secretion, and to maintain stability of the secretion pore in cooperation with a plug domain (R-plug) and a network of salt-bridges. The conservation of the M-gasket, R-plug, and salt-bridge network suggests a universal mechanism by which the membrane integrity is maintained during high-speed protein translocation in all T3SSs.< Leer menos
Palabras clave en inglés
type-III secretion
flagellum
Salmonella
membrane barrier
protein secretion
Centros de investigación