The tolC locus affects the expression of sbmA through σE activity increase.

The SbmA protein is involved in the transport of MccB17-, MccJ25-, bleomycin- and proline-rich peptides into the Escherichia coli cytoplasm. sbmA gene homologues were found in a variety of bacteria. However, the physiological role of this protein still remains unknown. Previously, we found that a co...

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Detalles Bibliográficos
Autores: Corbalan, Natalia Soledad, Adler, Conrado, de Cristobal, Ricardo Ezequiel, Pomares, Maria Fernanda, Delgado, Monica Alejandra, Vincent, Paula Andrea
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/97182
Acceso en línea:http://hdl.handle.net/11336/97182
Access Level:acceso abierto
Palabra clave:ΣE
SBMA REGULATION
TOLC
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:The SbmA protein is involved in the transport of MccB17-, MccJ25-, bleomycin- and proline-rich peptides into the Escherichia coli cytoplasm. sbmA gene homologues were found in a variety of bacteria. However, the physiological role of this protein still remains unknown. Previously, we found that a combination of sbmA and tolC mutations in Tn10-carrying E. coli K-12 strains results in hypersusceptibility to tetracycline. In this work, we studied sbmA expression in a tolC mutant background and observed an increased expression throughout growth. We ruled out the global transcriptional regulator RpoS and the small RNA micF as intermediates in this regulation. The tolC mutation induced the expression of other well-characterized strong σE- dependent promoters in E. coli. We observed that the increase in σE activity led to a greater sbmA expression, conversely eliminating σE prevented expression of sbmA. We also observed that the sbmA upregulation in a tolC mutant context was abolished in an rpoE-null strain. These results suggest a σE-dependent positive regulation on sbmA by the tolC mutation. We hypothesize that this mechanism might be part of a compensatory cell envelope stress response. © 2010 Federation of European Microbiological Societies.