A Search for Novel Effector Proteins Reveals a Strain Specific Nucleotropic Effector.

is an accidental human pathogen that causes the potentially fatal Legionnaires' disease, a severe type of pneumonia. The main virulence mechanism of is a Type 4B Secretion System (T4SS) named Icm/Dot that transports effector proteins into the host cell cytosol. The concerted action of effectors on several host cell processes leads to the formation of an intracellular Legionella-containing vacuole that is replication competent and avoids phagolysosomal degradation.