This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fernández-Mora, M. Articles by Calva, E. Search for Related Content PubMed PubMed Citation Articles by Fernández-Mora, M. Articles by Calva, E.

Next Article 

Journal of Bacteriology, May 2004, p. 2909-2920, Vol. 186, No. 10
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.10.2909-2920.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

OmpR and LeuO Positively Regulate the Salmonella enterica Serovar Typhi ompS2 Porin Gene

Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México

Received 16 November 2003/ Accepted 6 February 2004

The Salmonella enterica serovar Typhi ompS2 gene codes for a 362-amino-acid outer membrane protein that contains motifs common to the porin superfamily. It is expressed at very low levels compared to the major OmpC and OmpF porins, as observed for S. enterica serovar Typhi OmpS1, Escherichia coli OmpN, and Klebsiella pneumoniae OmpK37 quiescent porins. A region of 316 bp, between nucleotides –413 and –97 upstream of the transcriptional start point, is involved in negative regulation, as its removal resulted in a 10-fold increase in ompS2 expression in an S. enterica serovar Typhi wild-type strain. This enhancement in expression was not observed in isogenic mutant strains, which had specific deletions of the regulatory ompB (ompR envZ) operon. Furthermore, ompS2 expression was substantially reduced in the presence of the OmpR D55A mutant, altered in the major phosphorylation site. Upon random mutagenesis, a mutant where the transposon had inserted into the upstream regulatory region of the gene coding for the LeuO regulator, showed an increased level of ompS2 expression. Augmented expression of ompS2 was also obtained upon addition of cloned leuO to the wild-type strain, but not in an ompR isogenic derivative, consistent with the notion that the transposon insertion had increased the cellular levels of LeuO and with the observed dependence on OmpR. Moreover, LeuO and OmpR bound in close proximity, but independently, to the 5' upstream regulatory region. Thus, the OmpR and LeuO regulators positively regulate ompS2.

This article has been cited by other articles:

• Hernandez-Lucas, I., Gallego-Hernandez, A. L., Encarnacion, S., Fernandez-Mora, M., Martinez-Batallar, A. G., Salgado, H., Oropeza, R., Calva, E. (2008). The LysR-Type Transcriptional Regulator LeuO Controls Expression of Several Genes in Salmonella enterica Serovar Typhi. J. Bacteriol. 190: 1658-1670 [Abstract] [Full Text]  
• Stratmann, T., Madhusudan, S., Schnetz, K. (2008). Regulation of the yjjQ-bglJ Operon, Encoding LuxR-Type Transcription Factors, and the Divergent yjjP Gene by H-NS and LeuO. J. Bacteriol. 190: 926-935 [Abstract] [Full Text]  
• Rodriguez-Morales, O., Fernandez-Mora, M., Hernandez-Lucas, I., Vazquez, A., Puente, J. L., Calva, E. (2006). Salmonella enterica Serovar Typhimurium ompS1 and ompS2 Mutants Are Attenuated for Virulence in Mice. Infect. Immun. 74: 1398-1402 [Abstract] [Full Text]  
• Chen, C.-C., Wu, H.-Y. (2005). LeuO Protein Delimits the Transcriptionally Active and Repressive Domains on the Bacterial Chromosome. J. Biol. Chem. 280: 15111-15121 [Abstract] [Full Text]