Constituents of SH1, a novel lipid-containing virus infecting the halophilic euryarchaeon Haloarcula hispanica.
Recent studies have indicated that a number of bacterial and eukaryotic viruses that share a common architectural principle are related, leading to the proposal of an early common ancestor. A prediction of this model would be the discovery of similar viruses that infect archaeal hosts. Our main interest lies in icosahedral double-stranded DNA (dsDNA) viruses with an internal membrane, and we now extend our studies to include viruses infecting archaeal hosts. While the number of sequenced archaeal viruses is increasing, very little sequence similarity has been detected between bacterial and eukaryotic viruses. In this investigation we rigorously show that SH1, an icosahedral dsDNA virus infecting Haloarcula hispanica, possesses lipid structural components that are selectively acquired from the host pool. We also determined the sequence of the 31-kb SH1 genome and positively identified genes for 11 structural proteins, with putative identification of three additional proteins. The SH1 genome is unique and, except for a few open reading frames, shows no detectable similarity to other published sequences, but the overall structure of the SH1 virion and its linear genome with inverted terminal repeats is reminiscent of lipid-containing dsDNA bacteriophages like PRD1.
Department of Biological and Environmental Sciences, P.O. Box 56 (Viikinkaari 5), University of Helsinki, FIN-00014 Helsinki, Finland. jaana.bamford@helsinki.fi
Dennis H
DH
Bamford
Janne J
JJ
Ravantti
Gunilla
G
Rönnholm
Simonas
S
Laurinavicius
Petra
P
Kukkaro
Mike
M
Dyall-Smith
Pentti
P
Somerharju
Nisse
N
Kalkkinen
Jaana K H
JK
Bamford
D000595:Amino Acid Sequence; D025622:Bacteriophage PRD1 / Q000737:chemistry* / Q000235:genetics; D036022:Capsid Proteins / Q000737:chemistry; D016679:Genome, Viral; D019613:Haloarcula / Q000821:virology*; D008055:Lipids / Q000032:analysis*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D015678:Viral Structural Proteins / Q000032:analysis / Q000235:genetics
D036022:Capsid Proteins; D008055:Lipids; D015678:Viral Structural Proteins