This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Will, W. R.
Right arrow Articles by Frost, L. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Will, W. R.
Right arrow Articles by Frost, L. S.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2006, p. 507-514, Vol. 188, No. 2
0021-9193/06/$08.00+0     doi:10.1128/JB.188.2.507-514.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Characterization of the Opposing Roles of H-NS and TraJ in Transcriptional Regulation of the F-Plasmid tra Operon

William R. Will and Laura S. Frost*

Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada

Received 16 August 2005/ Accepted 24 October 2005

The transfer (tra) operon of the conjugative F plasmid of Escherichia coli is a polycistronic 33-kb operon which encodes most of the proteins necessary for F-plasmid transfer. Here, we report that transcription from PY, the tra operon promoter, is repressed by the host nucleoid-associated protein, H-NS. Electrophoretic mobility shift assays indicate that H-NS binds preferentially to the tra promoter region, while Northern blot and transcriptional fusion analyses indicate that transcription of traY, the first gene in the tra operon, is derepressed in an hns mutant throughout growth. The plasmid-encoded regulatory protein TraJ is essential for transcription of the tra operon in wild-type Escherichia coli; however, TraJ is not necessary for plasmid transfer or traY operon transcription in an hns mutant. This indicates that H-NS represses transcription from PY directly and not indirectly via its effects on TraJ levels. These results suggest that TraJ functions to disrupt H-NS silencing at PY, allowing transcription of the tra operon.

* Corresponding author. Mailing address: CW405 Biological Sciences Building, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada. Phone: (780) 492-0672. Fax: (780) 492-9234. E-mail: laura.frost{at}ualberta.ca.

Journal of Bacteriology, January 2006, p. 507-514, Vol. 188, No. 2
0021-9193/06/$08.00+0     doi:10.1128/JB.188.2.507-514.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • May, T., Okabe, S. (2008). Escherichia coli Harboring a Natural IncF Conjugative F Plasmid Develops Complex Mature Biofilms by Stimulating Synthesis of Colanic Acid and Curli. J. Bacteriol. 190: 7479-7490 [Abstract] [Full Text]  
  • Yang, X., Ma, Q., Wood, T. K. (2008). The R1 Conjugative Plasmid Increases Escherichia coli Biofilm Formation through an Envelope Stress Response. Appl. Environ. Microbiol. 74: 2690-2699 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»