JB
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 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 Whatmore, A. M.
Right arrow Articles by Dowson, C. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Whatmore, A. M.
Right arrow Articles by Dowson, C. G.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 1999, p. 3144-3154, Vol. 181, No. 10
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Genetic Diversity of the Streptococcal Competence (com) Gene Locus

Adrian M. Whatmore,* Victoria A. Barcus, and Christopher G. Dowson

Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom

Received 15 October 1998/Accepted 28 February 1999

The com operon of naturally transformable streptococcal species contains three genes, comC, comD, and comE, involved in the regulation of competence. The comC gene encodes a competence-stimulating peptide (CSP) thought to induce competence in the bacterial population at a critical extracellular concentration. The comD and comE genes are believed to encode the transmembrane histidine kinase and response regulator proteins, respectively, of a two-component regulator, with the comD-encoded protein being a receptor for CSP. Here we report on the genetic variability of comC and comD within Streptococcus pneumoniae isolates. Comparative analysis of sequence variations of comC and comD shows that, despite evidence for horizontal gene transfer at this locus and the lack of transformability of many S. pneumoniae strains in the laboratory, there is a clear correlation between the presence of a particular comC allele and the cognate comD allele. These findings effectively rule out the possibility that the presence of noncognate comC and comD alleles may be responsible for the inability to induce competence in many isolates and indicate the importance of a functional com pathway in these isolates. In addition, we describe a number of novel CSPs from disease-associated strains of S. mitis and S. oralis. The CSPs from these isolates are much more closely related to those from S. pneumoniae than to most CSPs previously reported from S. mitis and S. oralis, suggesting that these particular organisms may be a potential source of DNA in recombination events generating the mosaic structures commonly reported in genes of S. pneumoniae that are under strong selective pressure.

* Corresponding author. Mailing address: Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom. Phone: 44-1203-528359. Fax: 44-1203-523701. E-mail: a.m.whatmore{at}warwick.ac.uk.

Journal of Bacteriology, May 1999, p. 3144-3154, Vol. 181, No. 10
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1999 by the American Society for Microbiology. All rights reserved.