Divergent roles of RpoS in Escherichia coli under aerobic and anaerobic conditions.
FEMS Microbiol Lett
; 244(2): 323-7, 2005 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-15766785
ABSTRACT
Escherichia coli exhibited different levels of rpoS expression and general stress resistance under aerobiosis and anaerobiosis. Expression measured using reporter gene fusions and protein levels was lower under anaerobic conditions. Consistent with earlier findings, rpoS mutants were selected in aerobic nutrient-limited cultures but rpoS mutants were not enriched under anaerobiosis. This result suggested that, despite its decreased level, RpoS had a function under anaerobic conditions not essential under aerobiosis. Competition experiments between rpoS(+) and rpoS bacteria confirmed the advantage conferred by RpoS under anaerobiosis. In contrast, stress resistance assays suggested RpoS made a greater contribution to general stress resistance under aerobiosis than anaerobiosis. These results indicate a significant, but different role of RpoS in aerobic and anaerobic environments.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator sigma
/
Proteínas de Bactérias
/
Regulação Bacteriana da Expressão Gênica
/
Escherichia coli
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article