title: Physicochemical characterization of El Tor Vibriophage S20.
abstract: OBJECTIVE
  To characterize Vibrio cholerae El Tor typing phage S20 (ATCC No. 51352-B3).
  
  
  RESULTS
  The phage has a hexagonal head and a short tail. Cryo-electron microscopy and three-dimensional image reconstruction showed that the phage head has icosahedral symmetry. The phage has two major structural polypeptides of 50 and 42 kDa. Adsorption of the phage to its host followed a biphasic kinetics and its intracellular growth is characterized by a latent period of 12 min and a burst size of around 60 particles per infected cell. The phage was found to be stable at a pH range 5.0-9.0 and moderately thermotolerant and highly UV sensitive. Phage genome comprises a 40.7 +/- 1.5-kb linear DNA molecule with random circular permutation and terminal redundancy. The restriction endonucleases AccI, HpaII, HaeIII, HindIII, EcoRV, HincII, DraI and XmnI cut vibriophage S20 DNA.
  
  
  CONCLUSIONS
  Vibriophage S20, which belongs to Podoviridae, has an icosahedral head and the genome, which is double-stranded linear DNA, has random circular permutation and terminal redundancy.
authors.affiliation: Division of Electron Microscopy, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Moumita
authors.initials: M
authors.lastname: Dutta
authors.forename: Amar N
authors.initials: AN
authors.lastname: Ghosh
mesh_terms: D001435:Bacteriophages / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D008958:Models, Molecular; D017902:Podoviridae / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D014466:Ultraviolet Rays; D014734:Vibrio cholerae / Q000821:virology*; D014773:Virology / Q000379:methods; D038301:Virus Inactivation