Notes on Genus: Soymovirus
icosahedra
Type member: Soybean chlorotic mottle virus
Contents
General Description
This is one of 7 genera in the family
Caulimoviridae, which are distinctive amongst plant viruses in having double-stranded DNA. Members of this genus are those with isometric, rather than bacilliform particles and with 8 open reading frames in the genome. They were previously classified in the
Caulimovirus genus, but this now only includes those viruses with 6 or 7 open reading frames. The name is derived from the type member,
Soybean chlorotic
mottle virus.
Morphology
Virions isometric, not enveloped, 45-50 nm in diameter with no obvious surface structure. The virion shell is multi-layered.
Virions composed of 16 % nucleic acid.
Genome
Monopartite, open circular, double stranded DNA of
c.8200 base pairs.
Genus Genomic Organization
Eight potential open reading frames have been identified. The movement protein (1a), coat protein (4), reverse transcriptase (5) and post-trancriptional activator (6) are homologous to those of the genus
Caulimovirus, but the other ORFs are thought to function differently.
Type Member Genomic Organization
The proposed ORFs are:
| 1a | 35.6 kDa | Movement protein |
| 1b | 13.8 kDa | |
| 2 | 23.3 kDa | |
| 3 | 22.5 kDa | |
| 4 | 52.1 kDa | Coat protein |
| 5 | 80.4 kDa | Reverse transcriptase |
| 6 | 53.1 kDa | Possible post transcriptional activator |
| 7 | 17.1 kDa | |
| 8 | 9.6 kDa | possible ORF |
