This Article 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 Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Forst, S A Articles by Inouye, M Search for Related Content PubMed PubMed Citation Articles by Forst, S A Articles by Inouye, M

research-article

DNA-binding properties of the transcription activator (OmpR) for the upstream sequences of ompF in Escherichia coli are altered by envZ mutations and medium osmolarity.

Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854.

ABSTRACT

Expression in Escherichia coli of the genes that encode the major outer membrane porin proteins (OmpF and OmpC) is regulated by the transcription activator protein OmpR and the receptorlike protein EnvZ, which is located in the inner membrane. Using synthesized oligonucleotide fragments containing the OmpR-binding site of ompF, we show that soluble extracts and partially purified OmpR derived from both the parent strain grown in nutrient broth plus 20% sucrose and the envZ11 strain grown in nutrient broth produced high-affinity DNA-binding activity, whereas soluble extracts from the parent strain grown in nutrient broth produced low-affinity binding. We also show that the soluble extracts from the envZ22(Am) strain grown in nutrient broth did not produce detectable bound forms of the ompF fragments, but low levels of DNA binding were detected with soluble extracts of the envZ22 strain grown in nutrient broth plus sucrose. In addition, the time course of the repression of OmpF synthesis produced by a shift to high-osmolarity growth medium was correlated with an increase in the DNA-binding affinity of soluble extracts to the ompF fragment. These results provide evidence that envZ function influences the DNA-binding activity of OmpR and suggest that high-affinity binding of OmpR to the upstream sequences of ompF is correlated with the repression of OmpF production.

This article has been cited by other articles:

• He, H., Zahrt, T. C. (2005). Identification and Characterization of a Regulatory Sequence Recognized by Mycobacterium tuberculosis Persistence Regulator MprA. J. Bacteriol. 187: 202-212 [Abstract] [Full Text]  
• Walthers, D., Tran, V. K., Kenney, L. J. (2003). Interdomain Linkers of Homologous Response Regulators Determine Their Mechanism of Action. J. Bacteriol. 185: 317-324 [Abstract] [Full Text]  
• Cai, S. J., Inouye, M. (2002). EnvZ-OmpR Interaction and Osmoregulation in Escherichia coli. J. Biol. Chem. 277: 24155-24161 [Abstract] [Full Text]  
• Comolli, J. C., Carl, A. J., Hall, C., Donohue, T. (2002). Transcriptional Activation of the Rhodobacter sphaeroides Cytochrome c2 Gene P2 Promoter by the Response Regulator PrrA. J. Bacteriol. 184: 390-399 [Abstract] [Full Text]  
• Liu, X., Ferenci, T. (1998). Regulation of Porin-Mediated Outer Membrane Permeability by Nutrient Limitation in Escherichia coli. J. Bacteriol. 180: 3917-3922 [Abstract] [Full Text]  
• Harlocker, S. L., Bergstrom, L., Inouye, M. (1995). Tandem Binding of Six OmpR Proteins to the ompF Upstream Regulatory Sequence of Escherichia coli. J. Biol. Chem. 270: 26849-26856 [Abstract] [Full Text]  
• Jung, K., Hamann, K., Revermann, A. (2001). K+ Stimulates Specifically the Autokinase Activity of Purified and Reconstituted EnvZ of Escherichia coli. J. Biol. Chem. 276: 40896-40902 [Abstract] [Full Text]