DISSECTION OF THE YERSINIA-ENTEROCOLITICA VIRULENCE PLASMID PYV08 INTO AN OPERATING UNIT AND VIRULENCE GENE MODULES

The structural genes encoding the Yop proteins of Yersinia enterocolitica are scattered around on the virulence plasmid (pYV). The genes which are required for transactivation, secretion and translocation of the Yops are encoded in one cluster known as the Icr-region of pYV. After the introduction of an additional SalI restriction site into pYV of Y. enterocolitica serotype 08, we were able to clone and isolate the whole Ici-region on the mobilizable low copy vector pSUP102. Analysis of this construct in a plasmidless WA-strain showed that all Yops being encoded inside the Icr-region (YopN, YopB, YopD and the V-antigen) were secreted into the culture supernatant. Moreover, this Icr-fragment was able to promote secretion of other Yops encoded by a second recombinant plasmid. Thus the translocation and function of single Yops can be studied.