-termini of the genomic RNAs are capped, but not the 5-terminus of the encapsidated sgRNA. The 3-termini of the RNAs are similar to those of the genera Alfamovirus and Ilarvirus, but do not interact with CP to activate replication.
|
Type Species |
(OLV-2) |
Virions have different shape and size, ranging from quasi-spherical with a diameter of 26 nm, to bacilliform with lengths of 37, 43, 38, and 55 nm, and diameters of 18 nm. Particles up to 85 nm in length occasionally are present.
Physicochemical and Physical Properties
In sucrose gradients virions sediment as five or six components.
Virion RNA differs in size from other members of the family, encapsidating the three genomic RNAs and a sgRNA of about 2 kb, that is apparently not an mRNA. The sgRNA for the CP ORF is not encapsidated. Three additional RNAs of 200 to 550 nts are also present in virions. The 5-termini of the genomic RNAs are capped, but not the 5-terminus of the encapsidated sgRNA. The 3-termini of the RNAs are similar to those of the genera Alfamovirus and Ilarvirus, but do not interact with CP to activate replication.
Virions are efficient immunogens.
The only known host is olive (Olea europaea), which is infected asymptomatically. The virus is transmitted by inoculations, but no insect vector is known.
List of Species Demarcation Criteria in the Genus
Not applicable.
Official virus species names are in italics. Tentative virus species names, alternative names ( ), strains or serotypes are not italicized. Virus name, genome sequence accession numbers [ ], and assigned abbreviation ( ) are:
|
Olive latent virus 2 |
[X94346, X94327, X76933, X77115] |
(OLV-2) |
Tentative Species in the Genus
None reported.
List of Unassigned Species in the Family
None reported.
Phylogenetic Relationships within the Family
Not available.
The viruses are members of the “alpha-like” supergroup, sharing sequence similarity in the 1a protein domains for methyl-transferase and helicase activities, and in the 2a protein polymerase domain with members of the genera Tobravirus, Hordeivirus, Tobamovirus, Potexvirus, Carlavirus, and Tymovirus, and animal viruses in the family Togaviridae. The 3a proteins of the family Bromoviridae and the 35 kDa protein of the members of the genus Dianthovirus (RCNMV) form a distinct “family” of movement-associated proteins. Raspberry bushy dwarf virus (RBDV) has similarities in genome organization and in the sequence of certain genes with members of the family Bromoviridae, but is not considered a member of the family Bromoviridae.
Alfamo: derived from Alfalfa mosaic virus.
Bromo: derived from Brome mosaic, also, from Bromus (host of Brome mosaic virus).
Cucumo: derived from Cucumber mosaic virus.
Ilar: derived from isometric labile ringspot.
Olea: derived from the genus name of the host, olive (Olea).
|
|  |