THE ROLE OF NOVEL SURFACE PROTEINS IN YERSINIA PESTIS VIRULENCE

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Yersina pestis, the etiologic agent of plague, can bind to the surface, as well as invade, mammalian host cells during the infection process. This activity is an active area or research and a full understanding of the infection sequence leading to persistence in macrophages and lymphatic cells is essential in dissecting the pathogenicity of this important Gram negative bacterium. To this end, we generated a comprehensive TnphoA library to identify all surface proteins of Y. pestis. Analysis of this reporter fusion library identified a number of invasin like proteins by DNA sequence analysis. On candidate gene, the Yersinia pestis putative invasin protein (encoded by gene YPO3944 in Y. pestis CO92) is a large 3013 residue protein composed of a LysM motif, conserved in a subset of Gram negative bacterial invasion proteins, as well as tandem repeats of a bacterial Ig-like domain. Although this putative Y. pestis invasin protein is conserved in the genome of all sequenced Y. pestis biotypes, the exact role of this protein in the pathogenesis of Y.pestis has not been examined. Our specific goals for this project are to: 1. Determine the regulation of this gene under various environmental condtions using the phoA reporter system and real time PCR. 2. Generate a deletion mutation by site-directed mutagenesis and compare the virulence of this mutant with the wild-type parental strain in cell culture invasion assays and the mosue pathogenesis model.