The closest relatives of icosahedral viruses of thermophilic bacteria are among viruses and plasmids of the halophilic archaea.
We have sequenced the genome and identified the structural proteins and lipids of the novel membrane-containing, icosahedral virus P23-77 of Thermus thermophilus. P23-77 has an approximately 17-kb circular double-stranded DNA genome, which was annotated to contain 37 putative genes. Virions were subjected to dissociation analysis, and five protein species were shown to associate with the internal viral membrane, while three were constituents of the protein capsid. Analysis of the bacteriophage genome revealed it to be evolutionarily related to another Thermus phage (IN93), archaeal Halobacterium plasmid (pHH205), a genetic element integrated into Haloarcula genome (designated here as IHP for integrated Haloarcula provirus), and the Haloarcula virus SH1. These genetic elements share two major capsid proteins and a putative packaging ATPase. The ATPase is similar with the ATPases found in the PRD1-type viruses, thus providing an evolutionary link to these viruses and furthering our knowledge on the origin of viruses.
Jalasvuori
Matti
M
Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Finland.
Jaatinen
Silja T
ST
Laurinavicius
Simonas
S
Ahola-Iivarinen
Elina
E
Kalkkinen
Nisse
N
Bamford
Dennis H
DH
Bamford
Jaana K H
JK
D000251:Adenosine Triphosphatases / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics; D005798:Genes, Bacterial; D016680:Genome, Bacterial / Q000235:genetics*; D008055:Lipids; D008565:Membrane Proteins / Q000235:genetics; D010802:Phylogeny; D016963:Thermus thermophilus / Q000235:genetics*
D001426:Bacterial Proteins; D036022:Capsid Proteins; D008055:Lipids; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases