Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Circular structure of the genome of phage ϕH in a lysogenic Halobacterium halobium


Phage ϕH is a temperate phage, i.e., it can establish lysogeny in the archaebacterium Halobacterium halobium. ϕH-lysogens are immune to phage infection and phage production is spontaneously induced at a rate of about 10-7. In the prophage state. ϕH DNA exists as a covalently closed circle of 57 kb.

The frequent occurrence of clones carrying the phage genome but unable to produce phage is another proof of the high variability of DNA in H. halobium. In one such strain, R1-3, the phage genome has undergone a structural change which may have abolished an essential phage gene.

This is a preview of subscription content, log in to check access.


  1. Ikeda H, Tomizawa J (1968) Prophage P1. an extrachromosomal replication unit. Cold Spring Harbor Symp Quant Biol 33:791–798

  2. Pfeifer F, Weidinger G, Goebel W (1981) Characterization of plasmids in halobacteria. J Bacteriol 145:369–374

  3. Pfeifer F, Ebert K, Weidinger G, Goebel W (1982) Structure and functions of chromosomal and extrachromosomal DNA in halobacteria. Zbl Bakt Hyg I, Abt Orig C 3:110–119

  4. Schnabel H, Zillig W, Pfäffle M, Schnabel R, Michel H, Delius H (1982a) Halobacterium halobium phage ϕH. EMBO J 1:87–92

  5. Schnabel H, Schramm E, Schnabel R, Zillig W (1982b) Structural variability in the Genome of Phage ϕH of Halobacterium halobium. Mol Gen Genet 188:370–377

  6. Schnabel H (1984) An immune strain of Halobacterium halobium carries the invertible L segment of phage ϕH as a plasmid. Proc Natl Acad Sci USA, in press

  7. Torsvik T, Dundas ID (1980) Persisting phage infection in Halobacterium salinarium. J Gen Virol 47:29–36

  8. Weidinger G, Klotz G, Goebel W (1979) A large plasmid from Halobacterium halobium carrying genetic information for gas vacuole formation. Plasmid 2:377–386

  9. Xu W-L, Doolittle WF (1983) Structure of the archaebacterial transposable element ISH50. Nucleic Acids Res 11:4195–4199

Download references

Author information

Correspondence to Heinke Schnabel.

Additional information

Communicated by A. Böck

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Schnabel, H., Zillig, W. Circular structure of the genome of phage ϕH in a lysogenic Halobacterium halobium . Molec. Gen. Genet. 193, 422–426 (1984).

Download citation


  • Structural Change
  • High Variability
  • Frequent Occurrence
  • Halobacterium
  • Phage Genome