The DNA static curvature has a role in the regulation of the ompS1 porin gene in Salmonella enterica serovar Typhi

• Published in: Microbiology (Society for General Microbiology) Vol. 155; no. 7; pp. 2127 - 2136
• Main Authors: De la Cruz, Miguel Angel, Merino, Enrique, Oropeza, Ricardo, Tellez, Juan, Calva, Edmundo
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.07.2009; Society for General Microbiology
• Subjects: Bacterial Outer Membrane Proteins - biosynthesis; Bacterial Outer Membrane Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biological and medical sciences; Body Temperature Regulation; DNA, Bacterial - physiology; DNA-Binding Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Microbiology; Miscellaneous; Molecular Sequence Data; Mutagenesis, Site-Directed; Porins - biosynthesis; Porins - genetics; Regulatory Sequences, Nucleic Acid; Salmonella enterica; Salmonella typhi - genetics; Salmonella typhi - metabolism; Software; Transcription, Genetic; Water-Electrolyte Balance; Salmonella typhi; Bacteria; Porin; Gene; Enterobacteriaceae
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.028597-0

Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62260, Mexico The DNA static curvature has been described to play a key role as a regulatory element in the transcription process of several bacterial genes. Here, the role of DNA curvature in the expression of the ompS1 porin gene in Salmonella enterica serovar Typhi is described. The web server MUTACURVE was used to predict mutations that diminished or restored the extent of DNA curvature in the 5' regulatory region of ompS1 . Using these predictions, curvature was diminished by site-directed mutagenesis of only two residues, and curvature was restored by further mutagenesis of the same two residues. Lowering the extent of DNA curvature resulted in an increase in ompS1 expression and in the diminution of the affinity of the silencer proteins H-NS and StpA for the ompS1 5' regulatory region. These mutations were in a region shown not to contain the H-NS nucleation site, consistent with the notion that the effect on expression was due to changes in DNA structural topology. Correspondence Edmundo Calva ecalva{at}ibt.unam.mx Abbreviations: EMSA, electrophoretic mobility shift assay Related Article H-NS and genomic bridge building: lessons from the human pathogen Salmonella Typhi Charles J. Dorman Microbiology 2009 155: 2114-2115. [Full Text] [PDF]