title: A novel lipothrixvirus, SIFV, of the extremely thermophilic crenarchaeon Sulfolobus.
abstract: We describe a novel lipothrixvirus, SIFV, of the crenarchaeotal archaeon Sulfolobus islandicus. SIFV (S. islandicus filamentous virus) has a linear virion with a linear double-stranded DNA genome. These two features coincide in several crenarchaeotal but not in any other viruses. The SIFV core is formed by a zipper-like array of DNA-associated protein subunits and is covered by a lipid envelope containing host lipids. We sequenced approximately 96% of the virus genome excepting the DNA termini, which were modified in an unusual, yet uncharacterized, manner. Both, the 5' and the 3' DNA termini were insensitive to enzymatic degradation and labelling. Two open reading frames (ORFs) of the SIFV genome are likely to encode helicases and resemble uncharacterized ORFs from other archaea in sequence. Three ORFs showed sequence similarity with each other and each contained a glycosyl transferase motif. Another ORF of the SIFV genome showed significant sequence similarity to the ORF a291 from the well characterized, spindle-shaped Sulfolobus virus SSV1. Due to its structure, SIFV is classified as a lipothrixvirus.
authors.affiliation: Max-Planck-Institut für Biochemie, Martinsried, 82152, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Arnold
authors.forename: W
authors.initials: W
authors.lastname: Zillig
authors.forename: U
authors.initials: U
authors.lastname: Ziese
authors.forename: I
authors.initials: I
authors.lastname: Holz
authors.forename: M
authors.initials: M
authors.lastname: Crosby
authors.forename: T
authors.initials: T
authors.lastname: Utterback
authors.forename: J F
authors.initials: JF
authors.lastname: Weidmann
authors.forename: J K
authors.initials: JK
authors.lastname: Kristjanson
authors.forename: H P
authors.initials: HP
authors.lastname: Klenk
authors.forename: K E
authors.initials: KE
authors.lastname: Nelson
authors.forename: C M
authors.initials: CM
authors.lastname: Fraser
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D016679:Genome, Viral; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000821:virology*; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics; D014780:Viruses / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins