Notes on Genus: Allexivirus

flexuous filaments

Type member: Shallot virus X

Contents

Members of this Genus
General Description
Morphology
Electron Micrograph
Genome
Genus Genomic Organization
Genome Map
Type Member Genomic Organization
All Known Sequences
Curated Sequences

General Description

The genus Allexivirus is one of the genera in the family Alphaflexiviridae. In genome organisation it particularly resembles the genera Mandarivirus and Potexvirus but the third and smallest gene of the triple gene block is missing (or lacks a start codon) and ORF4 is a larger (c. 40 kDa) serine-rich protein. All the allexiviruses described so far infect members of the onion (Allium) genus, from which the name is derived.

Morphology

Virions filamentous, not enveloped, 700-800 nm long and 13 nm in diameter.

Genome

Monopartite, linear, single stranded, positive sense RNA of length c. 8000-9000 nucleotides. The 3' terminus has a poly(A) tract.

Genus Genomic Organization

Genes are translated from a total of 6 open reading frames:
1 170-195 kDa Polymerase, showing homology to ORF1 of members of the genus Potexvirus
2 25-28 kDa ORFs 2-3 (Triple gene block proteins 1 and 2):
translated from different reading frames
and probably involved in cell-to-cell movement.
3 11-12 kDa
4 32-43 kDaSerine-rich protein with no substantial homologies to proteins of other plant viruses
5 26-29 kDaCoat protein
6 14-15 kDaNucleic acid binding protein

Type Member Genomic Organization

Genes are translated from a total of 6 open reading frames:
1 195 kDa Polymerase, showing homology to ORF1 of members of the genus Potexvirus
2 26 kDa ORFs 2-3 (Triple gene block proteins 1 and 2):
translated from different reading frames
and probably involved in cell-to-cell movement.
3 11 kDa
4 42 kDaSerine-rich protein with no substantial homologies to proteins of other plant viruses
5 28 kDaCoat protein
6 15 kDaNucleic acid binding protein