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 Kharat, A. S.
Right arrow Articles by Tomasz, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kharat, A. S.
Right arrow Articles by Tomasz, A.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 2008, p. 5907-5914, Vol. 190, No. 17
0021-9193/08/$08.00+0     doi:10.1128/JB.00628-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Different Pathways of Choline Metabolism in Two Choline-Independent Strains of Streptococcus pneumoniae and Their Impact on Virulence{triangledown}

Arun S. Kharat,1,2 Dalia Denapaite,4,{dagger} Florian Gehre,1,{dagger} Reinhold Brückner,4 Waldemar Vollmer,3 Regine Hakenbeck,4 and Alexander Tomasz1*

Laboratory of Microbiology, The Rockefeller University, 1230 York Avenue, New York, New York 10021,1 Department of Biotechnology, Dr. Babasaheb Ambedkar Marathwada University, Sub-center-Osmanabad, MS, Pincode: 413 501, India,2 Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom,3 Department of Microbiology, University of Kaiserslautern, Kaiserslautern, Germany4

Received 6 May 2008/ Accepted 30 June 2008

The two recently characterized Streptococcus pneumoniae strains—R6Chi and R6Cho–—that have lost the unique auxotrophic requirement of this bacterial species for choline differ in their mechanisms of choline independence. In strain R6Chi the mechanism is caused by a point mutation in tacF, a gene that is part of the pneumococcal lic2 operon, which is essential for growth and survival of the bacteria. Cultures of lic2 mutants of the encapsulated strain D39Chi growing in choline-containing medium formed long chains, did not autolyze, had no choline in their cell wall, and were completely avirulent in the mouse intraperitoneal model. In contrast, while the Cho– strain carried a complete pneumococcal lic2 operon and had no mutations in the tacF gene, deletion of the entire lic2 operon had no effect on the growth or phenotype of strain Cho–. These observations suggest that the biochemical functions normally dependent on determinants of the pneumococcal lic2 operon may also be carried out in strain Cho– by a second set of genetic elements imported from Streptococcus oralis, the choline-independent streptococcal strain that served as the DNA donor in the heterologous transformation event that produced strain R6Cho–. The identification in R6Cho– of a large (20-kb) S. oralis DNA insert carrying both tacF and licD genes confirms this prediction and suggests that these heterologous elements may represent a "backup" system capable of catalyzing P-choline incorporation and export of teichoic acid chains under conditions in which the native lic2 operon is not functional.

* Corresponding author. Mailing address: Laboratory of Microbiology, The Rockefeller University, 1230 York Avenue, New York, NY 10021. Phone: (212) 327-8277. Fax: (212) 327-8688. E-mail: tomasz{at}rockefeller.edu

{triangledown} Published ahead of print on 11 July 2008.

{dagger} We consider the studies of Dalia Denapaite (identification of S. oralis DNA sequences) and Florian Gehre (characterization of the in vitro and in vivo phenotypes of mutants) to represent contributions of equal importance for the studies described in this article.

Journal of Bacteriology, September 2008, p. 5907-5914, Vol. 190, No. 17
0021-9193/08/$08.00+0     doi:10.1128/JB.00628-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Gehre, F., Spisek, R., Kharat, A. S., Matthews, P., Kukreja, A., Anthony, R. M., Dhodapkar, M. V., Vollmer, W., Tomasz, A. (2009). Role of Teichoic Acid Choline Moieties in the Virulence of Streptococcus pneumoniae. Infect. Immun. 77: 2824-2831 [Abstract] [Full Text]  
  • Baur, S., Marles-Wright, J., Buckenmaier, S., Lewis, R. J., Vollmer, W. (2009). Synthesis of CDP-Activated Ribitol for Teichoic Acid Precursors in Streptococcus pneumoniae. J. Bacteriol. 191: 1200-1210 [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»