Molecular Microbiology, Sept, 2012, Vol.85, p.1072(18)
To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2958.2012.08162.x/abstract Byline: Shane C. Dillon(1), Elena Espinosa(3), Karsten Hokamp(2), David W. Ussery(4), Josep Casadesus(3), Charles J. Dorman(1) Summary We report the first investigation of the binding of the Salmonella enterica LeuO LysR-type transcription regulator to its genomic targets in vivo. Chromatin-immunoprecipitation-on-chip identified 178 LeuO binding sites on the chromosome of S. enterica serovar Typhimurium strain SL1344. These sites were distributed across both the core and the horizontally acquired genome, and included housekeeping genes and genes known to contribute to virulence. Sixty-eight LeuO targets were co-bound by the global repressor protein, H-NS. Thus, while LeuO may function as an H-NS antagonist, these functions are unlikely to involve displacement of H-NS. RNA polymerase bound 173 of the 178 LeuO targets, consistent with LeuO being a transcription regulator. Thus, LeuO targets two classes of genes, those that are bound by H-NS and those that are not bound by H-NS. LeuO binding site analysis revealed a logo conforming to the TN.sub.11A motif common to LysR-type transcription factors. It differed in some details from a motif that we composed for Escherichia coli LeuO binding sites; 1263 and 1094 LeuO binding site locations were predicted in the S. Typhimurium SL1344 and E. coli MG1655 genomes respectively. Despite differences in motif composition, many LeuO target genes were common to both species. Thus, LeuO is likely to be a more important global regulator than previously suspected. Author Affiliation: (1)Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine (2)Department of Genetics, School of Genetics and Microbiology, Smurfit Institute, Trinity College Dublin, Dublin 2, Ireland (3)Departamento de Genetica, Facultad de Biologia, Universidad de Sevilla, Apartado 1095, Seville 41080, Spain (4)Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark Correspondence: (*) E-mail firstname.lastname@example.org; Tel. (+353) 1 8962013; Fax (+353) 1 6799294. Accepted 29 June, 2012. Supporting information: Additional Supporting Information may be found in the online version of this article
Transcription (Genetics) -- Genetic Aspects ; Transcription (Genetics) -- Analysis ; Bacterial Genetics -- Genetic Aspects ; Bacterial Genetics -- Analysis ; Preventive Medicine -- Analysis ; Dna Binding Proteins -- Genetic Aspects ; Dna Binding Proteins -- Analysis ; Genes -- Genetic Aspects ; Genes -- Analysis ; Rna -- Genetic Aspects ; Rna -- Analysis ; Salmonella -- Analysis
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