IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 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 Bohnsack, J. F.
Right arrow Articles by Adderson, E. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bohnsack, J. F.
Right arrow Articles by Adderson, E. E.

Infection and Immunity, September 2000, p. 5018-5025, Vol. 68, No. 9
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Genetic Polymorphisms of Group B Streptococcus scpB Alter Functional Activity of a Cell-Associated Peptidase That Inactivates C5a

John F. Bohnsack,1 Shinji Takahashi,2 Laura Hammitt,1 Dylan V. Miller,1 Adrienne A. Aly,1 and Elisabeth E. Adderson3,*

Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 381053; Departments of Pediatrics and Pathology, University of Utah School of Medicine, Salt Lake City, Utah 841321; and Department of Microbiology, Joshi-Eiyoh University, Sakado, Saitama 350-0288, Japan2

Received 4 October 1999/Returned for modification 29 November 1999/Accepted 2 June 2000

Many group B Streptococcus agalactiae strains and other pathogenic streptococci express a cell-associated peptidase that inactivates C5a (C5a-ase), the major neutrophil chemoattractant produced by activation of the complement cascade. Type III group B streptococci (GBS) can be classified genotypically into three restriction digest pattern types. Functional C5a-ase activity of GBS correlates with this genetic typing; therefore, we sought to identify a genetic basis for this phenomenon. Southern hybridization confirms that all type III GBS contain scpB, the gene encoding GBS C5a-ase. GBS strains with high C5a-ase functional activity and those with no or very low activity both express immunoreactive C5a-ase. The scpB sequence of strain I30, which has high C5a-ase activity, is 98.2% homologous to the previously reported serotype II GBS scpB sequence. The scpB sequences of strains I25 and GW, which have low or no C5a-ase activity, are identical. The predicted I25 and GW C5a-ase proteins share a four-amino-acid deletion affecting the protease histidine active-site consensus motif. Recombinant I30 C5a-ase has good functional activity, whereas recombinant I25 C5a-ase has low activity. These data demonstrate that functional C5a-ase differences between type III GBS strains are attributable to a genetic polymorphism of scpB. The ubiquitous expression of C5a-ase, irrespective of functional activity, suggests that C5a-ase may have a second, as yet unidentified, function.

* Corresponding author. Mailing address: Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 N. Lauderdale St., Memphis, TN 38105-2794. Phone: (901) 495-3459. Fax: (901) 495-3099. E-mail: Elisabeth.Adderson{at}STJUDE.org.

Infection and Immunity, September 2000, p. 5018-5025, Vol. 68, No. 9
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2000 by the American Society for Microbiology. All rights reserved.