Haemolysin coregulated protein is an exported receptor and chaperone of type VI secretion substrates.
Mol Cell
; 51(5): 584-93, 2013 Sep 12.
Article
en En
| MEDLINE
| ID: mdl-23954347
ABSTRACT
Secretion systems require high-fidelity mechanisms to discriminate substrates among the vast cytoplasmic pool of proteins. Factors mediating substrate recognition by the type VI secretion system (T6SS) of Gram-negative bacteria, a widespread pathway that translocates effector proteins into target bacterial cells, have not been defined. We report that haemolysin coregulated protein (Hcp), a ring-shaped hexamer secreted by all characterized T6SSs, binds specifically to cognate effector molecules. Electron microscopy analysis of an Hcp-effector complex from Pseudomonas aeruginosa revealed the effector bound to the inner surface of Hcp. Further studies demonstrated that interaction with the Hcp pore is a general requirement for secretion of diverse effectors encompassing several enzymatic classes. Though previous models depict Hcp as a static conduit, our data indicate it is a chaperone and receptor of substrates. These unique functions of a secreted protein highlight fundamental differences between the export mechanism of T6 and other characterized secretory pathways.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Pseudomonas aeruginosa
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Proteínas Bacterianas
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Sistemas de Secreción Bacterianos
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Proteínas Hemolisinas
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2013
Tipo del documento:
Article