Characteristics of PR5, a lipid-containing plasmid-dependent phage

Can J Microbiol. 1978 Jul;24(7):875-82. doi: 10.1139/m78-145.


An extensive characterization of plasmid-dependent phage PR5 isolated from sewage has been carried out. The phage has a head diameter of 65--68 nm, is isometric with a double-layered capsid, and a minority possess tails. It adsorbs to many but not all types of bacteria possessing P, N, or W plasmids. The phage contains 20% lipid, 15.1% DNA, and 64.9% protein by weight and has a buoyant density of 1.265 g/ml in CsCl. The DNA is double-stranded with a G + C content of 49% and a molecular weight of 7.4 +/- 0.6 x 10 (6) as shown by electron microscopy. Phospholipid content is 66% of lipid and consists of cardiolipin (13%), phosphatidylethanolamine (43%), and phosphatidylglycerol (44%) and differ quantitatively from that of host bacteria. Anti-PR5 serum inactivates other similar phages, PR3 and PR4. Phage adsorption is impaired in deep rough mutants of Salmonella minnesota.

MeSH terms

  • Bacteriophages* / growth & development
  • Bacteriophages* / ultrastructure
  • Conjugation, Genetic
  • DNA, Viral / analysis
  • Escherichia coli / genetics
  • Lipids / analysis
  • Lysogeny
  • Plasmids
  • Pseudomonas aeruginosa / genetics
  • Salmonella / genetics
  • Sewage
  • Viral Proteins / analysis
  • Water Microbiology*


  • DNA, Viral
  • Lipids
  • Sewage
  • Viral Proteins