A global role for Fis in the transcriptional control of metabolism and type III secretion in Salmonella enterica serovar Typhimurium.
Fis is a key DNA-binding protein involved in nucleoid organization and modulation of many DNA transactions, including transcription in enteric bacteria. The regulon of genes whose expression is influenced by Fis in Salmonella enterica serovar Typhimurium (S. typhimurium) has been defined by DNA microarray analysis. These data suggest that Fis plays a central role in coordinating the expression of both metabolic and type III secretion factors. The genes that were most strongly up-regulated by Fis were those involved in virulence and located in the pathogenicity islands SPI-1, SPI-2, SPI-3 and SPI-5. Similarly, motility and flagellar genes required Fis for full expression. This was shown to be a direct effect as purified Fis protein bound to the promoter regions of representative flagella and SPI-2 genes. Genes contributing to aspects of metabolism known to assist the bacterium during survival in the mammalian gut were also Fis-regulated, usually negatively. This category included components of metabolic pathways for propanediol utilization, biotin synthesis, vitamin B(12) transport, fatty acids and acetate metabolism, as well as genes for the glyoxylate bypass of the tricarboxylic acid cycle. Genes found to be positively regulated by Fis included those for ethanolamine utilization. The data reported reveal the central role played by Fis in coordinating the expression of both housekeeping and virulence factors required by S. typhimurium during life in the gut lumen or during systemic infection of host cells.
Kelly
Arlene
A
Department of Microbiology, Moyne Institute of Preventive Medicine, University of Dublin, Trinity College, Dublin 2, Ireland.
Goldberg
Martin D
MD
Molecular Microbiology Group, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
Carroll
Ronan K
RK
Department of Microbiology, Moyne Institute of Preventive Medicine, University of Dublin, Trinity College, Dublin 2, Ireland.
Danino
Vittoria
V
Molecular Microbiology Group, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
Hinton
Jay C D
JCD
Molecular Microbiology Group, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
Dorman
Charles J
CJ
Department of Microbiology, Moyne Institute of Preventive Medicine, University of Dublin, Trinity College, Dublin 2, Ireland.
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D035021:Factor For Inversion Stimulation Protein / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012486:Salmonella typhimurium / Q000378:metabolism* / Q000472:pathogenicity*; D014158:Transcription, Genetic; D014774:Virulence
D001426:Bacterial Proteins; D035021:Factor For Inversion Stimulation Protein