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 Scott, J.
Right arrow Articles by McShan, W. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Scott, J.
Right arrow Articles by McShan, W. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, October 2008, p. 6290-6301, Vol. 190, No. 19
0021-9193/08/$08.00+0     doi:10.1128/JB.01569-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Phage-Associated Mutator Phenotype in Group A Streptococcus{triangledown}

Julie Scott, Prestina Thompson-Mayberry, Stephanie Lahmamsi, Catherine J. King, and W. Michael McShan*

Department of Pharmaceutical Sciences, The University of Oklahoma College of Pharmacy, P.O. Box 26901, Oklahoma City, Oklahoma 73190

Received 28 September 2007/ Accepted 15 July 2008

Defects in DNA mismatch repair (MMR) occur frequently in natural populations of pathogenic and commensal bacteria, resulting in a mutator phenotype. We identified a unique genetic element in Streptococcus pyogenes strain SF370 that controls MMR via a dynamic process of prophage excision and reintegration in response to growth. In S. pyogenes, mutS and mutL are organized on a polycistronic mRNA under control of a common promoter. Prophage SF370.4 is integrated between the two genes, blocking expression of the downstream gene (mutL) and resulting in a mutator phenotype. However, in rapidly growing cells the prophage excises and replicates as an episome, allowing mutL to be expressed. Excision of prophage SF370.4 and expression of MutL mRNA occur simultaneously during early logarithmic growth when cell densities are low; this brief window of MutL gene expression ends as the cell density increases. However, detectable amounts of MutL protein remain in the cell until the onset of stationary phase. Thus, MMR in S. pyogenes SF370 is functional in exponentially growing cells but defective when resources are limiting. The presence of a prophage integrated into the 5' end of mutL correlates with a mutator phenotype (10–7 to 10–8 mutation/generation, an approximately a 100-fold increase in the rate of spontaneous mutation compared with prophage-free strains [10–9 to 10–10 mutation/generation]). Such genetic elements may be common in S. pyogenes since 6 of 13 completed genomes have related prophages, and a survey of 100 strains found that about 20% of them are positive for phages occupying the SF370.4 attP site. The dynamic control of a major DNA repair system by a bacteriophage is a novel method for achieving the mutator phenotype and may allow the organism to respond rapidly to a changing environment while minimizing the risks associated with long-term hypermutability.

* Corresponding author. Mailing address: Department of Pharmaceutical Sciences, The University of Oklahoma College of Pharmacy, P.O. Box 26901, Oklahoma City, OK 73190. Phone: (405) 271-6593. Fax: (405) 271-7505. E-mail: William-McShan{at}ouhsc.edu

{triangledown} Published ahead of print on 1 August 2008.

Journal of Bacteriology, October 2008, p. 6290-6301, Vol. 190, No. 19
0021-9193/08/$08.00+0     doi:10.1128/JB.01569-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Wood, D. N., Weinstein, K. E., Podbielski, A., Kreikemeyer, B., Gaughan, J. P., Valentine, S., Buttaro, B. A. (2009). Generation of Metabolically Diverse Strains of Streptococcus pyogenes during Survival in Stationary Phase. J. Bacteriol. 191: 6242-6252 [Abstract] [Full Text]  
  • McShan, W. M., Ferretti, J. J., Karasawa, T., Suvorov, A. N., Lin, S., Qin, B., Jia, H., Kenton, S., Najar, F., Wu, H., Scott, J., Roe, B. A., Savic, D. J. (2008). Genome Sequence of a Nephritogenic and Highly Transformable M49 Strain of Streptococcus pyogenes. J. Bacteriol. 190: 7773-7785 [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»