Evidence for Acquisition ofLegionellaType IV Secretion Substrates via Interdomain Horizontal Gene Transfer

• DOI: 10.1128/jb.187.22.7716-7726.2005
• Publication Date: 2005-11-02T22:07:52Z
• Authors: Karim Suwwan de F...; Sergey Pampou; Oliver S. Jovanovic; Christopher D. Pe...; Senna F. Ye; Sergey Kalachikov; Howard A. Shuman
• Keywords: Horizontal Gene Transfer; Gene transfer; Legionella

ABSTRACT Intracellular pathogens exploit host cell functions to create a replication niche inside eukaryotic cells. The causative agent of Legionnaires' disease, the γ-proteobacterium Legionella pneumophila , resides and replicates within modified vacuole protozoan mammalian L. translocates effector proteins into cells through Icm-Dot complex, specialized type IVB secretion system that is required for intracellular growth. To find out if some may have been acquired interdomain horizontal gene transfer (HGT), we performed bioinformatic screen searched motifs in all open reading frames Philadelphia-1 genome. We found 44 uncharacterized genes with many distinct motifs. Most these contain G+C biases compared other genes, supporting theory they were HGT. Furthermore, several them are expressed up-regulated stationary phase an RpoS-dependent manner. In addition, at least seven products translocated via confirming their role environment. Reminiscent case most substrates, strains containing mutations grew comparably parent strain intracellularly. Our findings suggest HGT major mechanism acquisition determinants infection.