a natural system of chromosome transfer in yersinia pseudotuberculosis自然系统的染色体转移就要伪.pdfVIP

A Natural System of Chromosome Transfer in Yersinia pseudotuberculosis 1 2 2 ` 1 1 Biliana Lesic , Mohamed Zouine , Magaly Ducos-Galand , Christele Huon , Marie-Laure Rosso , Marie- ´ 3 2 1 Christine Prevost , Didier Mazel *, Elisabeth Carniel * ´ ´ ´ ´ 1 Yersinia Research Unit, Institut Pasteur, Paris, France, 2 Unite Plasticite du Genome Bacterien, Institut Pasteur, CNRS UMR 3525, Paris, France, 3 Plateforme de Microscopie Ultrastructurale, Institut Pasteur, Paris, France Abstract The High Pathogenicity Island of Yersinia pseudotuberculosis IP32637 was previously shown to be horizontally transferable as part of a large chromosomal segment. We demonstrate here that at low temperature other chromosomal loci, as well as a non-mobilizable plasmid (pUC4K), are also transferable. This transfer, designated GDT4 (Generalized DNA Transfer at 4uC), required the presence of an IP32637 endogenous plasmid (pGDT4) that carries several mobile genetic elements and a conjugation machinery. We established that cure of this plasmid or inactivation of its sex pilus fully abrogates this process. Analysis of the mobilized pUC4K recovered from transconjugants revealed the insertion of one of the pGDT4–borne ISs, designated ISYps1, at different sites on the transferred plasmid molecules. This IS belongs to the IS6 family, which moves by replicative transposition, and thus could drive the formation of cointegrates between pGDT4 and the host chromosome and could mediate the transfer of chromosomal regions in an Hfr-like manner. In support of this model, we show that a suicide plasm