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. Author manuscript; available in PMC: 2016 Apr 27.
Published in final edited form as: Trends Microbiol. 2000 Aug;8(8):354–360. doi: 10.1016/s0966-842x(00)01792-3

Table 1.

Substrates of type IV systemsa

System Substrate(s) Consequence(s) of transfer
Plasmid conjugation Transfer intermediate (ss DNA)
  covalently bound at 59 end to
  transesterase; primase; SSB;
  RecA		 Dissemination of virulence and antibiotic-resistance
  genes; transferred proteins contribute to
  establishment of plasmid in recipient
Agrobacterium
  tumefaciens T-DNA
  transfer		 T-DNA (ss T-DNA/VirD2); VirE2;
  VirF		 Oncogenesis (crown gall disease); T-DNA delivery to
  plant nucleus; broadened host range
Bordetella pertussis Ptl Pertussis toxin ADP-ribosylation of GTP-binding proteins
Helicobacter pylori Cag 145-kDa CagA protein Tyrosine phosphorylation of CagA; formation of CagA
  cylinders; host cell cytoskeletal rearrangements
Legionella pneumophila
  Dot/Icm		 Unknown effector Allows survival and growth in macrophages;
  prevent phagosome/lysosome fusion?
IncQ plasmid Plasmid acquisition by L. pneumophila recipients
  Lvh IncQ plasmid Plasmid acquisition by L. pneumophila recipients
Brucella, Bartonella,
  Rickettsia 		Unknown Aid in intracellular survival?
a

Abbreviation: SSB, single-stranded-DNA-binding protein.