Volume 26, Issue 1 pp. 99-107
Free Access

The ClpP protein, a subunit of the Clp protease, modulates ail gene expression in Yersinia enterocolitica

Kristin J. Pederson

Kristin J. Pederson

Department of Microbiology, University of Colorado Health Sciences Center, Campus Box B175, 4200 E. Ninth Avenue, Denver, CO 80262, USA.

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Sharon Carlson

Sharon Carlson

Department of Microbiology, University of Colorado Health Sciences Center, Campus Box B175, 4200 E. Ninth Avenue, Denver, CO 80262, USA.

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Dorothy E. Pierson

Dorothy E. Pierson

Department of Microbiology, University of Colorado Health Sciences Center, Campus Box B175, 4200 E. Ninth Avenue, Denver, CO 80262, USA.

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First published: 31 October 2003
Citations: 36
Dorothy E. Pierson E-mail dorothy. [email protected]; Tel. (303) 315 5285; Fax (303) 315 6785.

Abstract

Yersinia enterocolitica is a gastrointestinal pathogen of humans and animals. Ail is a 17 kDa cell-surface protein that confers on Y. enterocolitica resistance to serum killing and the ability to attach to and invade cells in vitro. The ail gene of Y. enterocolitica is regulated by temperature and growth phase. In stationary phase, ail transcript is only detected when bacteria are grown at the host temperature of 37°C. Our laboratory previously described a group of mini-Tn10 mutants, which expressed ail in stationary phase at 28°C. In one of these mutants, DP5102::mini-Tn10 3-2, the mini-Tn10 inserted into a gene encoding a protein with 90.3% identity to the ClpP protease subunit from Escherichia coli. Expression of ail in stationary phase at 28°C was also derepressed in a directed Y. enterocolitica clpP mutant. Analysis of ail transcripts in the wild-type and clpP mutant strains indicated that there is a single start site of transcription of ail and that the effect of the clpP mutation was on the initiation of transcription at this site. Similar to E. coli, a clpX homologue was identified downstream of clpP. The Y. enterocolitica clpP gene complemented the clpP mutant phenotype, repressing the expression of both ail transcript levels and cell surface-expressed Ail protein. Thus, ClpP has a role in the modulation of ail transcription in Y. enterocolitica.

Footnotes

  • Present address: Department of Microbiology, Medical College of Wisconsin, USA
    • The full text of this article hosted at iucr.org is unavailable due to technical difficulties.