Identification and characterization of a second, inducible promoter of relA in Escherichia coli

Autor:	Akira Nakagawa, Taku Oshima, Hirotada Mori
Rok vydání:	2006
Předmět:	RELA Base Sequence Stringent response Molecular Sequence Data Mutant lac operon Gene Expression Regulation Bacterial General Medicine Biology medicine.disease_cause Molecular biology Ligases Gene expression Escherichia coli Genetics medicine Promoter Regions Genetic Molecular Biology rpoS Alarmone
Zdroj:	Genes & Genetic Systems. 81:299-310
ISSN:	1880-5779 1341-7568
Popis:	The alarmone ppGpp is an important signal molecule for the stringent response. Escherichia coli relA encodes a ppGpp synthetase, and although the regulation of RelA protein activity has been studied extensively, the regulation of relA transcription remains unclear. Here, we describe a novel relA promoter, relAP2. According to quantitative measurement of mRNA by primer extension analysis, the previously reported promoter relAP1 is constitutively active throughout growth, while relAP2 is induced temporarily at the transition state between the exponential growth and stationary phases. A chromosomal transcriptional lacZ fusion (relAP2-lacZ) showed that relAP2 is positively regulated by H-NS and CRP. Furthermore, the reduced activity of relAP2-lacZ in an hns mutant could be rescued by an rpoS mutation, which is sufficient to derepress the relAP2-lacZ activity. These data suggest that transient expression from the relAP2 promoter is controlled by several global regulators. This may account for the complex regulation of relA expression in Escherichia coli.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::821d123998ffbcf3a36f9b7556166101 https://doi.org/10.1266/ggs.81.299 Zobrazit plný text záznamu