title: Vesicle-like virion of Haloarcula hispanica pleomorphic virus 3 preserves high infectivity in saturated salt.
abstract: Hypersaline environments that are subject to salinity changes are particularly rich in viruses. Here we report a newly isolated archaeal halovirus, Haloarcula hispanica pleomorphic virus 3 (HHPV3). Its reproduction significantly retards host growth and decreases cell viability without causing lysis. HHPV3 particles require a minimum of 3M NaCl for stability and maintain high infectivity even in saturated salt. Notably, virions are irreversibly inactivated at ~1.5M NaCl in neutral pH, but tolerate this salinity at alkaline pH. The HHPV3 virion is a pleomorphic membrane vesicle containing two major protein species and lipids acquired nonselectively from the host membrane. The circular double-stranded DNA genome contains a conserved gene block characteristic of pleolipoviruses. We propose that HHPV3 is a member of the Betapleolipovirus genus (family Pleolipoviridae). Our findings add insights into the diversity observed among the pleolipoviruses found in hypersaline environments.
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Viikinkaari 9, 00014, Finland.
authors.forename: Tatiana A
authors.initials: TA
authors.lastname: Demina
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Viikinkaari 9, 00014, Finland.
authors.forename: Nina S
authors.initials: NS
authors.lastname: Atanasova
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Viikinkaari 9, 00014, Finland.
authors.forename: Maija K
authors.initials: MK
authors.lastname: Pietilä
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Viikinkaari 9, 00014, Finland. Electronic address: hanna.oksanen@helsinki.fi.
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Oksanen
authors.affiliation: Institute of Biotechnology and Department of Biosciences, University of Helsinki, Viikinkaari 9, 00014, Finland.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Bamford
mesh_terms: D023641:Archaeal Viruses / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D023061:Gene Order; D016679:Genome, Viral; D019613:Haloarcula / Q000821:virology*; D058507:Host Specificity; D006863:Hydrogen-Ion Concentration; D007477:Ions; D016366:Open Reading Frames; D054712:Salinity; D014771:Virion / Q000302:isolation & purification / Q000502:physiology / Q000648:ultrastructure; D014779:Virus Replication
chemical_list: D007477:Ions
keywords: Archaeal virus; Genome sequence; Halovirus; Hypersalinity; Pleolipoviridae; Pleomorphic virus; Virus life cycle