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 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 Sharif, T R Articles by Igo, M M Search for Related Content PubMed PubMed Citation Articles by Sharif, T R Articles by Igo, M M

research-article

Mutations in the alpha subunit of RNA polymerase that affect the regulation of porin gene transcription in Escherichia coli K-12.

Department of Microbiology, University of California, Davis 95616.

ABSTRACT

The two-component regulatory system consisting of OmpR and EnvZ controls the differential expression of major outer membrane porin proteins OmpF and OmpC of Escherichia coli K-12. We have isolated and characterized two mutations in rpoA, the gene encoding the alpha subunit of RNA polymerase, that decrease the expression of OmpF. These mutations have a number of properties that distinguish them from previously isolated rpoA mutations that affect porin expression. The rpoA203 mutation decreases the expression of porin genes ompF and ompC and also decreases the expression of the malE and phoA genes. In contrast, rpoA207 decreases the expression of ompF but does not affect ompC, malE, or phoA transcription. Our results suggest that mutations at various positions in the alpha subunit may affect the OmpR-dependent transcription of ompF and ompC differently and may be useful for analyzing the mechanism underlying their differential expression in response to medium osmolarity.

This article has been cited by other articles:

• Goh, E.-B., Siino, D. F., Igo, M. M. (2004). The Escherichia coli tppB (ydgR) Gene Represents a New Class of OmpR-Regulated Genes. J. Bacteriol. 186: 4019-4024 [Abstract] [Full Text]  
• Cheung, J. K., Rood, J. I. (2000). The VirR Response Regulator from Clostridium perfringens Binds Independently to Two Imperfect Direct Repeats Located Upstream of the pfoA Promoter. J. Bacteriol. 182: 57-66 [Abstract] [Full Text]  
• Raivio, T. L., Popkin, D. L., Silhavy, T. J. (1999). The Cpx Envelope Stress Response Is Controlled by Amplification and Feedback Inhibition. J. Bacteriol. 181: 5263-5272 [Abstract] [Full Text]