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 Santini, J. M.
Right arrow Articles by Stanisich, V. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Santini, J. M.
Right arrow Articles by Stanisich, V. A.

 Previous Article  |  Next Article 

Journal of Bacteriology, August 1998, p. 4093-4101, Vol. 180, No. 16
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Both the fipA Gene of pKM101 and the pifC Gene of F Inhibit Conjugal Transfer of RP1 by an Effect on traG

Joanne M. Santini and Vilma A. Stanisich*

Department of Microbiology, La Trobe University, Bundoora 3083, Australia

Received 9 February 1998/Accepted 2 June 1998

The mechanisms by which gene products inhibit the conjugal transfer of IncP plasmids (e.g., RP1) have been little studied. We have isolated and characterized one such gene, fipA (624 nucleotides), from the SmaI (14.8 kb)-AatII (15.6 kb) region of pKM101(IncN). This gene, which is also conserved in other IncN plasmids, is transcribed in an anticlockwise direction, probably as part of a transfer operon that includes traHI. The FipA protein (24 kDa) appears to be cytoplasmic and, when expressed from a multicopy plasmid, retards the growth of Escherichia coli WP2. The mode of action of fipA was compared with that of the apparently unrelated pifC gene from F(IncFI). Both genes inhibit the transfer of IncPalpha and IncPbeta plasmids but to different degrees. They also inhibit the mobilization of RSF1010 (which requires the RP1 pilus genes and traG) but not of CloDF13 (which encodes a traG homolog). Evidence that traG was the specific target of inhibition was obtained in an artificial system in which cloned traG was used to enhance RSF1010 mobilization via the N pilus system. Such enhancement did not occur in the presence of fipA or pifC. The availability of an in vivo assay of PifC enabled us to show that F pif operon expression increased in cells carrying F'lac and traG, but only if the traG coding sequence was intact. This finding suggested that conjugal inhibition of RP1 was most likely due to a PifC-TraG protein interaction. On phenotypic grounds inhibition of traG by fipA is also likely to occur posttranscriptionally. Whether or not the selection of traG as the inhibition target is an evolutionary tactic to limit the spread of P plasmids, we anticipate that fipA and pifC will prove useful in further investigation of the conjugal roles of traG and its homologs.

* Corresponding author. Mailing address: Department of Microbiology, La Trobe University, Bundoora 3083, Australia. Phone: (613) 9479 2317. Fax: (613) 9479 1222. E-mail: vilma{at}lumi.latrobe.edu.au.

Journal of Bacteriology, August 1998, p. 4093-4101, Vol. 180, No. 16
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Fricke, W. F., Welch, T. J., McDermott, P. F., Mammel, M. K., LeClerc, J. E., White, D. G., Cebula, T. A., Ravel, J. (2009). Comparative Genomics of the IncA/C Multidrug Resistance Plasmid Family. J. Bacteriol. 191: 4750-4757 [Abstract] [Full Text]  
  • Poirel, L., Cattoir, V., Soares, A., Soussy, C.-J., Nordmann, P. (2007). Novel Ambler Class A {beta}-Lactamase LAP-1 and Its Association with the Plasmid-Mediated Quinolone Resistance Determinant QnrS1. Antimicrob. Agents Chemother. 51: 631-637 [Abstract] [Full Text]  
  • Hormaeche, I., Alkorta, I., Moro, F., Valpuesta, J. M., Goni, F. M., de la Cruz, F. (2002). Purification and Properties of TrwB, a Hexameric, ATP-binding Integral Membrane Protein Essential for R388 Plasmid Conjugation. J. Biol. Chem. 277: 46456-46462 [Abstract] [Full Text]  
  • Gomis-Ruth, F. X., Moncalian, G., de la Cruz, F., Coll, M. (2002). Conjugative Plasmid Protein TrwB, an Integral Membrane Type IV Secretion System Coupling Protein. DETAILED STRUCTURAL FEATURES AND MAPPING OF THE ACTIVE SITE CLEFT. J. Biol. Chem. 277: 7556-7566 [Abstract] [Full Text]  
  • Skaugen, M., Andersen, E. L., Christie, V. H., Nes, I. F. (2002). Identification, Characterization, and Expression of a Second, Bicistronic, Operon Involved in the Production of Lactocin S in Lactobacillus sakei L45. Appl. Environ. Microbiol. 68: 720-727 [Abstract] [Full Text]  
  • Moncalian, G., Cabezon, E., Alkorta, I., Valle, M., Moro, F., Valpuesta, J. M., Goni, F. M., de la Cruz, F. (1999). Characterization of ATP and DNA Binding Activities of TrwB, the Coupling Protein Essential in Plasmid R388 Conjugation. J. Biol. Chem. 274: 36117-36124 [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»