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 Larsen, R. A.
Right arrow Articles by Postle, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Larsen, R. A.
Right arrow Articles by Postle, K.

 Previous Article  |  Next Article 

Journal of Bacteriology, August 2003, p. 4699-4706, Vol. 185, No. 16
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.16.4699-4706.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Performance of Standard Phenotypic Assays for TonB Activity, as Evaluated by Varying the Level of Functional, Wild-Type TonB

Ray A. Larsen,{dagger} Gregory J. Chen, and Kathleen Postle*

School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-4234

Received 8 January 2003/ Accepted 15 May 2003

The ability of gram-negative bacterial cells to transport cobalamin and iron-siderophore complexes and their susceptibility to killing by some bacteriophages and colicins are characteristics routinely used to assay mutations of proteins in the TonB-dependent energy transduction system. These assays vary greatly in sensitivity and are subject to perturbation by overexpression of TonB and, perhaps, other proteins that contribute to the process. Thus, the choice of assay and the means by which a potential mutant is expressed can greatly influence the interpretation and recognition of a given mutant. In the present study, we expressed TonB at several different quantified levels in cells that were then subjected to a panel of assays. Our results suggest that it is reasonable to regard the assays as having windows of sensitivity. Thus, while no single assay satisfactorily spans the potential range of TonB activity, it is evident that certain assays are better suited for resolving small deviations from wild-type levels of activity, with others most useful when activity levels are very low. It is apparent from the results that the application of all possible assays to the characterization of new mutants will yield the most meaningful results.

* Corresponding author. Mailing address: School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4234. Phone: (509) 335-5614. Fax: (509) 335-1907. E-mail: postle{at}wsu.edu.

{dagger} Present address: Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0212.

Journal of Bacteriology, August 2003, p. 4699-4706, Vol. 185, No. 16
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.16.4699-4706.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Brinkman, K. K., Larsen, R. A. (2008). Interactions of the Energy Transducer TonB with Noncognate Energy-Harvesting Complexes. J. Bacteriol. 190: 421-427 [Abstract] [Full Text]  
  • Vakharia-Rao, H., Kastead, K. A., Savenkova, M. I., Bulathsinghala, C. M., Postle, K. (2007). Deletion and Substitution Analysis of the Escherichia coli TonB Q160 Region. J. Bacteriol. 189: 4662-4670 [Abstract] [Full Text]  
  • Larsen, R. A., Deckert, G. E., Kastead, K. A., Devanathan, S., Keller, K. L., Postle, K. (2007). His20 Provides the Sole Functionally Significant Side Chain in the Essential TonB Transmembrane Domain. J. Bacteriol. 189: 2825-2833 [Abstract] [Full Text]  
  • Cascales, E., Buchanan, S. K., Duche, D., Kleanthous, C., Lloubes, R., Postle, K., Riley, M., Slatin, S., Cavard, D. (2007). Colicin Biology. Microbiol. Mol. Biol. Rev. 71: 158-229 [Abstract] [Full Text]  
  • Mora, L., Diaz, N., Buckingham, R. H., de Zamaroczy, M. (2005). Import of the Transfer RNase Colicin D Requires Site-Specific Interaction with the Energy-Transducing Protein TonB. J. Bacteriol. 187: 2693-2697 [Abstract] [Full Text]  
  • Letoffe, S., Delepelaire, P., Wandersman, C. (2004). Free and Hemophore-Bound Heme Acquisitions through the Outer Membrane Receptor HasR Have Different Requirements for the TonB-ExbB-ExbD Complex. J. Bacteriol. 186: 4067-4074 [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»