Notes on Genus: Enamovirus
icosahedra
Type member: Pea enation mosaic virus-1
Contents
General Description
The genus
Enamovirus (from the type member pea
enation
mosaic virus 1) is one of three genera in the family
Luteoviridae and currently has only one member. Until recently it was considered as an irreversible mixed infection of two autonomously replicating RNAs, but the current taxonomy retains only the old RNA1 (which has some similarity to members of the genus
Polerovirus) as an enamovirus and places the old RNA2 as a different virus (Pea enation mosaic virus-2) in the genus
Umbravirus.
Morphology
Virions isometric (polyhedral), not enveloped, of two sizes, 25 and 28 nm in diameter.
Genome
Monopartite, linear, single stranded, positive sense RNA about 5700 nt long. The 3'-terminus has neither a poly(A) tract nor a tRNA-like structure, and the 5'- terminus has a genome-linked protein.
Genus Genomic Organization
The genome (5706 nucleotides) has many similarities to members of the genus
Polerovirus but lacks the functions for systemic movement and mechanical transmission, which are supplied by Pea enation mosaic virus-2, in the genus
Umbravirus, with which it is invariably associated. .
Type Member Genomic Organization
There are five ORFs:
1. | ORF 0 | 34 kDa | unknown function |
2. | ORF 1 | 84 kDa | Replication protein |
3. | ORF 2 | 67 kDa | Polymerase |
4. | ORF 3 | 21 kDa | Coat protein |
5. | ORF 5 | 54 kDa | Coat protein readthrough |
These ORFs are numbered to be consistent with other members of the family
Luteoviridae.