title: Growth-phase-dependent mobility of the lvh-encoding region in Legionella pneumophila strain Paris.
abstract: The lvh region of the Legionella pneumophila genome, which encodes a type IV secretion system, is located on a plasmid-like element in strains Paris (pP36) and Philadelphia (pLP45). The pP36 element has been described either integrated in the chromosome or excised as a multi-copy plasmid, in a similar manner to pLP45. In this paper, the chromosomal integration of pP36 in the Paris strain genome was described, occurring through site-specific recombination at the 3' end of a transfer-messenger RNA gene by recombination between attachment sites, in a similar manner to pathogenicity islands. This integration was growth-phase dependent, occurring during the exponential phase. Several pP36-borne genes were expressed during the lag phase of bacterial growth, coinciding with the peak amount of the episomal form of pP36. Expression of the same genes decreased during the exponential and stationary phases, owing to the integration phenomenon and a loss of episomal copies of pP36. A similar plasmid-like element was described in the Lens strain genome, suggesting that the mobility of the lvh region is a phenomenon widespread among Legionella sp.
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: Anne
authors.initials: A
authors.lastname: Doléans-Jordheim
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: Mongi
authors.initials: M
authors.lastname: Akermi
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Ginevra
authors.affiliation: Unité de Génomique des Micro-organismes Pathogènes, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Christel
authors.initials: C
authors.lastname: Cazalet
authors.affiliation: Laboratoire Adaptation et Pathogénie des Micro-organismes, CNRS UMR5163, Université Joseph Fourier-Institut Jean Roget, 38700 La Tronche, France.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kay
authors.affiliation: Laboratoire Adaptation et Pathogénie des Micro-organismes, CNRS UMR5163, Université Joseph Fourier-Institut Jean Roget, 38700 La Tronche, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Schneider
authors.affiliation: Unité de Génomique des Micro-organismes Pathogènes, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Carmen
authors.initials: C
authors.lastname: Buchrieser
authors.affiliation: Unité de Microbiologie et Génétique UMR 5122, Université Claude Bernard Lyon 1, Bât. Lwoff, 10 rue Dubois, 69622 Villeurbanne, France.
authors.forename: Danièle
authors.initials: D
authors.lastname: Atlan
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: François
authors.initials: F
authors.lastname: Vandenesch
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: Jerome
authors.initials: J
authors.lastname: Etienne
authors.affiliation: INSERM, E0230, Lyon, F-69008 France; Université Lyon 1, Centre National de référence des Legionella, Faculté Laennec, Lyon, F-69008 France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Jarraud
mesh_terms: D001287:Attachment Sites, Microbiological / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D002876:Chromosomes, Bacterial / Q000235:genetics*; D015870:Gene Expression; D020071:Interspersed Repetitive Sequences; D016952:Legionella pneumophila / Q000235:genetics* / Q000254:growth & development; D010957:Plasmids / Q000235:genetics*; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins; C459580:Lvh protein, Legionella pneumophila; D012329:RNA, Bacterial; D012333:RNA, Messenger