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 Almengor, A. C.
Right arrow Articles by McIver, K. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Almengor, A. C.
Right arrow Articles by McIver, K. S.

 Previous Article  |  Next Article 

Journal of Bacteriology, December 2004, p. 7847-7857, Vol. 186, No. 23
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.23.7847-7857.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Transcriptional Activation of sclA by Mga Requires a Distal Binding Site in Streptococcus pyogenes

Audry C. Almengor and Kevin S. McIver*

Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas

Received 16 July 2004/ Accepted 30 August 2004

Streptococcus pyogenes (the group A streptococcus [GAS]) is a medically significant pathogen of humans, causing a range of diseases from pharyngitis to necrotizing fasciitis. Several important GAS virulence genes are under the control of a pleiotropic regulator called Mga, or the multiple gene regulator of GAS, including the gene encoding the streptococcal collagen-like protein, or sclA. Analysis of the genome sequence upstream of sclA revealed two potential Mga-binding sites with homology to the published Mga-binding element, which were called PsclA-I (distal) and PsclA-II (proximal) based on their location relative to a predicted start of transcription. Primer extension was used to confirm that the Mga-dependent transcriptional start site for sclA was located adjacent to the proximal PsclA-II binding site. By using overlapping PsclA promoter probes and purified Mga-His fusion protein, it was shown by electrophoretic mobility shift assays that, unlike other Mga-regulated promoters, Mga binds only to a distal DNA-binding site (PsclA-I). Binding of Mga to PsclA-I could be competed with cold probes corresponding to known Mga-regulated promoters (Pemm, PscpA, and Pmga) but not with a nonspecific probe or the proximal PsclA-II fragment. With the use of a plasmid-based green fluorescent protein transcriptional reporter system, the full-length PsclA was not sufficient to reproduce normal Mga-regulated activation. However, studies using a single-copy gusA transcriptional reporter system integrated at the native sclA chromosomal locus clearly demonstrated that the distal PsclA-I binding site is required for Mga regulation. Therefore, PsclA represents a new class of Mga-regulated promoters that requires a single distal binding site for activation.

* Corresponding author. Mailing address: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9048. Phone: (214) 648-1255. Fax: (214) 648-5907. E-mail: Kevin.Mciver{at}UTSouthwestern.edu.

Journal of Bacteriology, December 2004, p. 7847-7857, Vol. 186, No. 23
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.23.7847-7857.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Almengor, A. C., Kinkel, T. L., Day, S. J., McIver, K. S. (2007). The Catabolite Control Protein CcpA Binds to Pmga and Influences Expression of the Virulence Regulator Mga in the Group A Streptococcus. J. Bacteriol. 189: 8405-8416 [Abstract] [Full Text]  
  • Deutscher, J., Francke, C., Postma, P. W. (2006). How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria. Microbiol. Mol. Biol. Rev. 70: 939-1031 [Abstract] [Full Text]  
  • Almengor, A. C., Walters, M. S., McIver, K. S. (2006). Mga Is Sufficient To Activate Transcription In Vitro of sof-sfbX and Other Mga-Regulated Virulence Genes in the Group A Streptococcus. J. Bacteriol. 188: 2038-2047 [Abstract] [Full Text]  
  • Vahling, C. M., McIver, K. S. (2006). Domains Required for Transcriptional Activation Show Conservation in the Mga Family of Virulence Gene Regulators. J. Bacteriol. 188: 863-873 [Abstract] [Full Text]  
  • Vahling, C. M., McIver, K. S. (2005). Identification of Residues Responsible for the Defective Virulence Gene Regulator Mga Produced by a Natural Mutant of Streptococcus pyogenes. J. Bacteriol. 187: 5955-5966 [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»