Carbapenem antibiotic biosynthesis in Erwinia carotovora is regulated by physiological and genetic factors modulating the quorum sensing-dependent control pathway.
Mol Microbiol
; 55(2): 526-45, 2005 Jan.
Article
en En
| MEDLINE
| ID: mdl-15659168
ABSTRACT
Erwinia carotovora produces the beta-lactam antibiotic, carbapenem, in response to a quorum sensing signalling molecule, N-(3-oxohexanoyl)-L-homoserine lactone (OHHL). We have mapped the OHHL-dependent promoter upstream of the first of the biosynthetic genes, carA. We have also analysed the effect on this promoter of the known genetic regulators of carbapenem expression, carR, carI (encoding homologues of LuxR and LuxI respectively) and hor (encoding a SlyA/MarR-like transcriptional regulator). We describe a previously unknown promoter located within the carA-H operon. This promoter does not respond to CarR and is required for quorum sensing-independent expression of the carbapenem resistance determinants encoded by the carFG genes. We have mapped the carR, carI and hor transcription start points, shown that CarR is positively autoregulated in the presence of OHHL, and have demonstrated negative feedback affecting transcription of carI. In addition, various environmental and physiological factors were shown to impinge on the transcription of the car biosynthetic genes. The nature of the carbon source and the temperature of growth influence carbapenem production by modulating the level of the OHHL signalling molecule, and thereby physiologically fine-tune the quorum sensing regulatory system.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
/
4-Butirolactona
/
Transducción de Señal
/
Carbapenémicos
/
Regulación Bacteriana de la Expresión Génica
/
Pectobacterium carotovorum
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Reino Unido