title: Structure of the archaeal head-tailed virus HSTV-1 completes the HK97 fold story.
abstract: It has been proposed that viruses can be divided into a small number of structure-based viral lineages. One of these lineages is exemplified by bacterial virus Hong Kong 97 (HK97), which represents the head-tailed dsDNA bacteriophages. Seemingly similar viruses also infect archaea. Here we demonstrate using genomic analysis, electron cryomicroscopy, and image reconstruction that the major coat protein fold of newly isolated archaeal Haloarcula sinaiiensis tailed virus 1 has the canonical coat protein fold of HK97. Although it has been anticipated previously, this is physical evidence that bacterial and archaeal head-tailed viruses share a common architectural principle. The HK97-like fold has previously been recognized also in herpesviruses, and this study expands the HK97-like lineage to viruses from all three domains of life. This is only the second established lineage to include archaeal, bacterial, and eukaryotic viruses. Thus, our findings support the hypothesis that the last common universal ancestor of cellular organisms was infected by a number of different viruses.
authors.affiliation: Department of Biosciences and Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland.
authors.forename: Maija K
authors.initials: MK
authors.lastname: Pietilä
authors.forename: Pasi
authors.initials: P
authors.lastname: Laurinmäki
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Russell
authors.forename: Ching-Chung
authors.initials: CC
authors.lastname: Ko
authors.forename: Deborah
authors.initials: D
authors.lastname: Jacobs-Sera
authors.forename: Roger W
authors.initials: RW
authors.lastname: Hendrix
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Bamford
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Butcher
mesh_terms: D023641:Archaeal Viruses / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure*; D002213:Capsid / Q000737:chemistry / Q000648:ultrastructure; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics; D003198:Computer Simulation; D020285:Cryoelectron Microscopy; D016679:Genome, Viral; D019613:Haloarcula / Q000821:virology*; D021621:Imaging, Three-Dimensional; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding
chemical_list: D036022:Capsid Proteins
keywords: archaeal virus; major capsid protein fold; virus evolution