Open AccessIdentification of the σ E regulon of Salmonella enterica serovar Typhimurium
Author(s) -
Henrieta Škovierová,
Gary Rowley,
Bronislava Řežuchová,
Dagmar Homerová,
Claire E. Lewis,
Mark Roberts,
Ján Kormanec
Publication year - 2006
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 179
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.28744-0
Subject(s) - regulon , sigma factor , promoter , biology , salmonella enterica , periplasmic space , rna polymerase , gene , plasmid , bacterial outer membrane , genetics , rpon , escherichia coli , microbiology and biotechnology , gene expression
The extracytoplasmic function sigma factor, σ E , has been shown to play a critical role in virulence of Salmonella enterica serovar Typhimurium ( S. Typhimurium). The previously optimized two-plasmid system has been used to identify S. Typhimurium promoters recognized by RNA polymerase containing σ E . This method allowed identification of 34 σ E -dependent promoters that direct expression of 62 genes in S. Typhimurium, 23 of which (including several specific for S. Typhimurium) have not been identified previously to be dependent upon σ E in Escherichia coli . The promoters were confirmed in S. Typhimurium and transcriptional start points of the promoters were determined by S1-nuclease mapping. All the promoters contained sequences highly similar to the consensus sequence of σ E -dependent promoters. The identified genes belonging to the S. Typhimurium σ E -regulon encode proteins involved in primary metabolism, DNA repair systems and outer-membrane biogenesis, and regulatory proteins, periplasmic proteases and folding factors, proposed lipoproteins, and inner- and outer-membrane proteins with unknown functions. Several of these σ E -dependent genes have been shown to play a role in virulence of S. Typhimurium.