HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Bearden, S. W. Articles by Brubaker, R. R. Search for Related Content PubMed PubMed Citation Articles by Bearden, S. W. Articles by Brubaker, R. R. Agricola Articles by Bearden, S. W. Articles by Brubaker, R. R.

Attenuated enzootic (pestoides) isolates of Yersinia pestis express active aspartase

¹ Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases, Bacterial Diseases Branch, Fort Collins, CO 80521, USA
² Department of Microbiology and Molecular Genetics, Michigan State University, 2215 Biomedical Physical Sciences, East Lansing, MI 48824, USA
³ Department of Chemistry, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606, USA
⁴ Department of Microbiology, The University of Chicago, 920 E. 58th Street, Chicago, IL 60637, USA

Correspondence
Robert R. Brubaker
t-rbruba{at}bsd.uchicago.edu

It is established that Yersinia pestis, the causative agent of bubonic plague, recently evolved from enteropathogenic Yersinia pseudotuberculosis by undergoing chromosomal degeneration while acquiring two unique plasmids that facilitate tissue invasion (pPCP) and dissemination by fleabite (pMT). Thereafter, plague bacilli spread from central Asia to sylvatic foci throughout the world. These epidemic isolates exhibit a broad host range including man as opposed to enzootic (pestoides) variants that remain in ancient reservoirs where infection is limited to muroid rodents. Cells of Y. pseudotuberculosis are known to express glucose-6-phosphate dehydrogenase (Zwf) and aspartase (AspA); these activities are not detectable in epidemic Y. pestis due to missense mutations (substitution of proline for serine at amino position 155 of Zwf and leucine for valine at position 363 of AspA). In this study, functional Zwf was found in pestoides strains E, F and G but not seven other enzootic isolates; enzymic activity was associated with retention of serine at amino acid position 155. Essentially, full AspA activity occurred in pestoides isolates where valine (pestoides A, B, C and D) or serine (pestoides E, F, G and I) occupied position 363. Reduced activity occurred in strains Angola and A16, which contained phenylalanine at this position. The k_cat but not K_m of purified AspA from strain Angola was significantly reduced. In this context, aspA of the recently described attenuated enzootic microtus biovar encodes active valine at position 363, further indicating that functional AspA is a biomarker for avirulence of Y. pestis in man.

This article has been cited by other articles:

				D. Zhou and R. Yang Molecular Darwinian Evolution of Virulence in Yersinia pestis Infect. Immun., June 1, 2009; 77(6): 2242 - 2250. [Full Text] [PDF]