title: Familial relationships in hyperthermo- and acidophilic archaeal viruses.
abstract: Archaea often live in extreme, harsh environments such as acidic hot springs and hypersaline waters. To date, only two icosahedrally symmetric, membrane-containing archaeal viruses, SH1 and Sulfolobus turreted icosahedral virus (STIV), have been described in detail. We report the sequence and three-dimensional structure of a third such virus isolated from a hyperthermoacidophilic crenarchaeon, Sulfolobus strain G4ST-2. Characterization of this new isolate revealed it to be similar to STIV on the levels of genome and structural organization. The genome organization indicates that these two viruses have diverged from a common ancestor. Interestingly, the prominent surface turrets of the two viruses are strikingly different. By sequencing and mass spectrometry, we mapped several large insertions and deletions in the known structural proteins that could account for these differences and showed that both viruses can infect the same host. A combination of genomic and proteomic analyses revealed important new insights into the structural organization of these viruses and added to our limited knowledge of archaeal virus life cycles and host-cell interactions.
authors.affiliation: Institute of Biotechnology and Department of Biosciences, Biocenter 3, P.O. Box 65 (Viikinkaari 1), FI-00014 University of Helsinki, Helsinki, Finland.
authors.forename: Lotta Johanna
authors.initials: LJ
authors.lastname: Happonen
authors.forename: Peter
authors.initials: P
authors.lastname: Redder
authors.forename: Xu
authors.initials: X
authors.lastname: Peng
authors.forename: Laila Johanne
authors.initials: LJ
authors.lastname: Reigstad
authors.forename: David
authors.initials: D
authors.lastname: Prangishvili
authors.forename: Sarah Jane
authors.initials: SJ
authors.lastname: Butcher
mesh_terms: D023641:Archaeal Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D016000:Cluster Analysis; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D016679:Genome, Viral; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020543:Proteome / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D016944:Sulfolobus / Q000145:classification / Q000235:genetics / Q000821:virology*; D026801:Synteny; D014764:Viral Proteins / Q000032:analysis; D014771:Virion / Q000648:ultrastructure*
chemical_list: D019641:DNA, Archaeal; D004275:DNA, Ribosomal; D004279:DNA, Viral; D020543:Proteome; D012336:RNA, Ribosomal, 16S; D014764:Viral Proteins