Open AccessRegulation of spvR , the positive regulatory gene of Salmonella plasmid virulence genes
Author(s) -
Spink Jayne M.,
Pullinger Gillian D.,
Wood Michael W.,
Lax Alistair J.
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb06684.x
Subject(s) - operon , plasmid , biology , gene , virulence , lac operon , reporter gene , salmonella , regulation of gene expression , gene expression , genetics , bacteria , escherichia coli
The regulation of the spvR promoter from the Salmonella dublin virulence plasmid was monitored using proter‐reporter gene fusion constructs. Activity was dependent upon the presence of the spv region and was affected by the number of copies of the spv region present with the cell. Activity remained constant throughout exponential growth, and increased rapidly with the onset of stationary phase, under both aerobic and anaerobic conditions. Additionally, the level of spvR expression was controlled by the availability of iron, activity being greatest under low iron conditions in stationary phase. The spvA gene product negatively regulated spvR expression in a dose‐dependent manner, indicating that SpvA provides a negative feedback mechanism for this operon.