title: Closely related archaeal Haloarcula hispanica icosahedral viruses HHIV-2 and SH1 have nonhomologous genes encoding host recognition functions.
abstract: Studies on viral capsid architectures and coat protein folds have revealed the evolutionary lineages of viruses branching to all three domains of life. A widespread group of icosahedral tailless viruses, the PRD1-adenovirus lineage, was the first to be established. A double β-barrel fold for a single major capsid protein is characteristic of these viruses. Similar viruses carrying genes coding for two major capsid proteins with a more complex structure, such as Thermus phage P23-77 and haloarchaeal virus SH1, have been isolated. Here, we studied the host range, life cycle, biochemical composition, and genomic sequence of a new isolate, Haloarcula hispanica icosahedral virus 2 (HHIV-2), which resembles SH1 despite being isolated from a different location. Comparative analysis of these viruses revealed that their overall architectures are very similar except that the genes for the receptor recognition vertex complexes are unrelated even though these viruses infect the same hosts.
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Salla T
authors.initials: ST
authors.lastname: Jaakkola
authors.forename: Reetta K
authors.initials: RK
authors.lastname: Penttinen
authors.forename: Silja T
authors.initials: ST
authors.lastname: Vilén
authors.forename: Matti
authors.initials: M
authors.lastname: Jalasvuori
authors.forename: Gunilla
authors.initials: G
authors.lastname: Rönnholm
authors.forename: Jaana K H
authors.initials: JK
authors.lastname: Bamford
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Bamford
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Oksanen
mesh_terms: D023641:Archaeal Viruses / Q000235:genetics* / Q000472:pathogenicity; D005075:Biological Evolution; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D005814:Genes, Viral; D016679:Genome, Viral; D019613:Haloarcula / Q000821:virology; D054884:Host-Pathogen Interactions / Q000235:genetics; D008969:Molecular Sequence Data; D017385:Sequence Homology; D014771:Virion / Q000737:chemistry / Q000235:genetics; D014774:Virulence
chemical_list: D036022:Capsid Proteins