Legionella pneumophila contains a type II general secretion pathway required for growth in amoebae as well as for secretion of the Msp protease.
We report the identification of a set of Legionella pneumophila genes that encode products with homology to proteins of the type II general secretion pathway of gram-negative bacteria. A strain containing a deletion-substitution mutation of two of these genes was unable to secrete the Msp protease. This strain was unable to multiply within the free-living amoeba Acanthamoeba castellanii yet was able to kill HL-60-derived macrophages. Because Msp is not required for growth in amoebae, other proteins which are important for growth in amoebae are likely secreted by this pathway.
Hales
L M
LM
Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Shuman
H A
HA
D000048:Acanthamoeba / Q000382:microbiology*; D000818:Animals; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D016952:Legionella pneumophila / Q000502:physiology*; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics
D012697:Serine Endopeptidases