Three small RNAs jointly ensure secondary metabolism and biocontrol in Pseudomonas fluorescens CHA0.
Proc Natl Acad Sci U S A
; 102(47): 17136-41, 2005 Nov 22.
Article
en En
| MEDLINE
| ID: mdl-16286659
ABSTRACT
In many Gram-negative bacteria, the GacS/GacA two-component system positively controls the expression of extracellular products or storage compounds. In the plant-beneficial rhizosphere bacterium Pseudomonas fluorescens CHA0, the GacS/GacA system is essential for the production of antibiotic compounds and hence for biological control of root-pathogenic fungi. The small (119-nt) RNA RsmX discovered in this study, together with RsmY and RsmZ, forms a triad of GacA-dependent small RNAs, which sequester the RNA-binding proteins RsmA and RsmE and thereby antagonize translational repression exerted by these proteins in strain CHA0. This small RNA triad was found to be both necessary and sufficient for posttranscriptional derepression of biocontrol factors and for protection of cucumber from Pythium ultimum. The same three small RNAs also positively regulated swarming motility and the synthesis of a quorum-sensing signal, which is unrelated to N-acyl-homoserine lactones, and which autoinduces the Gac/Rsm cascade. Expression of RsmX and RsmY increased in parallel throughout cell growth, whereas RsmZ was produced during the late growth phase. This differential expression is assumed to facilitate fine tuning of GacS/A-controlled cell population density-dependent regulation in P. fluorescens.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Represoras
/
Proteínas Bacterianas
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Pseudomonas fluorescens
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ARN Bacteriano
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Regulación Bacteriana de la Expresión Génica
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ARN Citoplasmático Pequeño
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2005
Tipo del documento:
Article
País de afiliación:
Suiza