TABLE 5.

Analysis of C. burnetii icm homologous genes in L. pneumophila icm mutants

GroupProteinPredicted locationaHomology (% identity/% similarity)bIntracellular growthcPore formationC. burnetii complementationd
C. burnetiiR64HL-60A. castellaniiHL-60A. castellanii
1IcmTeIM47.1/63.224.5/32.3+±
IcmPIM36.5/50.320.0/33.3
IcmOIM59.6/70.923.8/35.5
IcmJCyt51.2/61.918.7/29.8
IcmBCyt62.2/73.726.2/39.6
2IcmSCyt52.6/67.5±+++
IcmWCyt58.6/68.4±+++
3IcmXPerp21.9/30.219.3/26.9
4IcmQCyt22.6/34.0
  • a Predicted bacterial cellular locations of the Icm proteins. IM, inner membrane; Cyt, cytoplasm; Perp, periplasm.

  • b The levels of homology between the L. pneumophila and C. burnetii Icm proteins and between the L. pneumophila Icm proteins and the R64 plasmid Tra/Trb proteins were calculated. Similar amino acids are I, L, V, and M; H, K, and R; D and E; T and S; and Q and N. —, no homologous protein was found.

  • c The sources of the intracellular growth phenotypes are icmT, icmS, icmQ, icmP, and icmO (51, 54); icmJ and icmB (44, 54); icmW (72; this study); and icmX (5, 54). −, mutants cannot grow intracellulalrly ±, partial phenotype for intracellular growth.

  • d −, no complementation (Fig. 3B); ±, partial complementation (Fig. 1A); +, complete complementation (Fig. 1B, 2, and 3A).

  • e The icmT rib mutants were shown to be defective in exiting from the phagosome in amoebae (38).