Identification and characterization of a new conjugation/type IVA secretion system (trb/tra) of Legionella pneumophila Corby localized on two mobile genomic islands.

Horizontal gene transfer probably contributes to evolution of Legionella pneumophila and its adaptation to different environments. Although horizontal gene transfer was observed in Legionella, the mechanism is still not specified. In this study we identified and analysed a new type of conjugation/type IVA secretion system (trb/tra) of L.

Characterization of the alternative sigma factor sigma54 and the transcriptional regulator FleQ of Legionella pneumophila, which are both involved in the regulation cascade of flagellar gene expression.

We cloned and analyzed Legionella pneumophila Corby homologs of rpoN (encoding sigma(54)) and fleQ (encoding sigma(54) activator protein). Two other genes (fleR and pilR) whose products have a sigma(54) interaction domain were identified in the genome sequence of L. pneumophila.

Description of a putative type I secretion system in Legionella pneumophila.

Here we describe the first putative type I secretion system of L. pneumophila. The lssXYZABD locus was found to be present in all L.