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 Zähner, D.
Right arrow Articles by Scott, J. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zähner, D.
Right arrow Articles by Scott, J. R.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2008, p. 527-535, Vol. 190, No. 2
0021-9193/08/$08.00+0     doi:10.1128/JB.01520-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

SipA Is Required for Pilus Formation in Streptococcus pyogenes Serotype M3{triangledown}

Dorothea Zähner and June R. Scott*

Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322

Received 20 September 2007/ Accepted 26 October 2007

Pili are a major surface feature of the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). The T3 pilus is composed of a covalently linked polymer of protein T3 (formerly Orf100 or Fct3) with an ancillary protein, Cpa, attached. A putative signal peptidase, SipA (also called LepA), has been identified in several pilus gene clusters of GAS. We demonstrate that the SipA2 allele of a GAS serotype M3 strain is required for synthesis of T3 pili. Heterologous expression in Escherichia coli showed that SipA2, along with the pilus backbone protein T3 and the sortase SrtC2, is required for polymerization of the T3 protein. In addition, we found that SipA2 is also required for linkage of the ancillary pilin protein Cpa to polymerized T3. Despite partial conservation of motifs of the type I signal peptidase family proteins, SipA lacks the highly conserved and catalytically important serine and lysine residues of these enzymes. Substitution of alanine for either of the two serine residues closest to the expected location of an active site serine demonstrated that these serine residues are both dispensable for T3 polymerization. Therefore, it seems unlikely that SipA functions as a signal peptidase. However, a T3 protein mutated at the P-1 position of the signal peptide cleavage site (alanine to arginine) was unstable in the presence of SipA2, suggesting that there is an interaction between SipA and T3. A possible chaperone-like function of SipA2 in T3 pilus formation is discussed.

* Corresponding author. Mailing address: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322. Phone: (404) 727-0402. Fax: (404) 727-8999. E-mail: scott{at}microbio.emory.edu

{triangledown} Published ahead of print on 9 November 2007.

Journal of Bacteriology, January 2008, p. 527-535, Vol. 190, No. 2
0021-9193/08/$08.00+0     doi:10.1128/JB.01520-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Nakata, M., Koller, T., Moritz, K., Ribardo, D., Jonas, L., McIver, K. S., Sumitomo, T., Terao, Y., Kawabata, S., Podbielski, A., Kreikemeyer, B. (2009). Mode of Expression and Functional Characterization of FCT-3 Pilus Region-Encoded Proteins in Streptococcus pyogenes Serotype M49. Infect. Immun. 77: 32-44 [Abstract] [Full Text]  
  • LeMieux, J., Woody, S., Camilli, A. (2008). Roles of the Sortases of Streptococcus pneumoniae in Assembly of the RlrA Pilus. J. Bacteriol. 190: 6002-6013 [Abstract] [Full Text]  
  • Nobbs, A. H., Rosini, R., Rinaudo, C. D., Maione, D., Grandi, G., Telford, J. L. (2008). Sortase A Utilizes an Ancillary Protein Anchor for Efficient Cell Wall Anchoring of Pili in Streptococcus agalactiae. Infect. Immun. 76: 3550-3560 [Abstract] [Full Text]  
  • Bagnoli, F., Moschioni, M., Donati, C., Dimitrovska, V., Ferlenghi, I., Facciotti, C., Muzzi, A., Giusti, F., Emolo, C., Sinisi, A., Hilleringmann, M., Pansegrau, W., Censini, S., Rappuoli, R., Covacci, A., Masignani, V., Barocchi, M. A. (2008). A Second Pilus Type in Streptococcus pneumoniae Is Prevalent in Emerging Serotypes and Mediates Adhesion to Host Cells. J. Bacteriol. 190: 5480-5492 [Abstract] [Full Text]  
  • Luo, F., Lizano, S., Bessen, D. E. (2008). Heterogeneity in the Polarity of Nra Regulatory Effects on Streptococcal Pilus Gene Transcription and Virulence. Infect. Immun. 76: 2490-2497 [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»