Notes on Genus: Cytorhabdovirus
Type member: Lettuce necrotic yellows virus
This is one of 2 plant virus genera in the family Rhabdoviridae
. It was previously known as Plant Rhabdovirus group A. The genus is characterised by its bacilliform, enveloped, particles which contain a monopartite ssRNA genome and which mature in the cytoplasm of the host plant cell. The name derives from the Greek cyto
= cell and rhabdos
Virions regular in shape and size to pleomorphic in shape and size (in unfixed preparations), bacilliform (when fixed prior to negative staining), enveloped, 200-350 nm long and 70-95 nm in diameter. There are distinct surface projections (spikes) dispersed evenly over all the surface. Nucleocapsids filamentous (when uncoiled), with obvious regular cross-banding and with a distinct central canal. Symmetry helical with pitch of 4.2-4.7 nm.
Virions composed of 1 % nucleic acid, 70 % protein and 25 % lipid.
Monopartite, linear, single-stranded, negative sense RNA, 11000-15000 nucleotides long.
Genus Genomic Organization
The genome organisation is typical of the family with the "standard" genes N, P, M, G and L in order on the template strand. Depending on the species, there are one or more additional genes located between P and M.
Type Member Genomic Organization
There are 6 genes which are listed here in their order on the template strand (i.e. from 3' to 5' with respect to the virion strand):
|ORF|| Gene ||Product||Function|
|1 ||N ||50.7 kDa||Coat protein (nucleocapsid) |
|2 ||P||32.5 kDa||Phosphoprotein |
|3 ||4b||33.7 kDa||unknown function |
|4 ||M ||19.5 kda||Matrix protein |
|5 ||G||62.3 kda ||Glycoprotein |
|6 ||L||236.6 kDa ||Polymerase|