Structure and Membrane Topography of the Vibrio-Type Secretin Complex from the Type 2 Secretion System of Enteropathogenic Escherichia coli.
J Bacteriol
; 200(5)2018 03 01.
Article
em En
| MEDLINE
| ID: mdl-29084860
ABSTRACT
The ß-barrel assembly machinery (BAM) complex is the core machinery for the assembly of ß-barrel membrane proteins, and inhibition of BAM complex activity is lethal to bacteria. Discovery of integral membrane proteins that are key to pathogenesis and yet do not require assistance from the BAM complex raises the question of how these proteins assemble into bacterial outer membranes. Here, we address this question through a structural analysis of the type 2 secretion system (T2SS) secretin from enteropathogenic Escherichia coli O127H6 strain E2348/69. Long ß-strands assemble into a barrel extending 17 Å through and beyond the outer membrane, adding insight to how these extensive ß-strands are assembled into the E. coli outer membrane. The substrate docking chamber of this secretin is shown to be sufficient to accommodate the substrate mucinase SteC.IMPORTANCE In order to cause disease, bacterial pathogens inhibit immune responses and induce pathology that will favor their replication and dissemination. In Gram-negative bacteria, these key attributes of pathogenesis depend on structures assembled into or onto the outer membrane. One of these is the T2SS. The Vibrio-type T2SS mediates cholera toxin secretion in Vibrio cholerae, and in Escherichia coli O127H6 strain E2348/69, the same machinery mediates secretion of the mucinases that enable the pathogen to penetrate intestinal mucus and thereby establish deadly infections.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Proteínas da Membrana Bacteriana Externa
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Secretina
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Escherichia coli Enteropatogênica
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Sistemas de Secreção Tipo II
Idioma:
En
Revista:
J Bacteriol
Ano de publicação:
2018
Tipo de documento:
Article