Notes on Genus: Trichovirus

flexuous filaments

Type member: Apple chlorotic leaf spot virus

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 Trichovirus (named from the Greek thrix =hair) is one of the genera in the family Betaflexiviridae. It contains viruses originally included tentatively in the genus Closterovirus, but which have shorter virions, a very different genome organisation and a poly(A) tail.

Morphology

Virions filamentous and flexuous, not enveloped, 640-800 nm long and 12 nm in diameter. Nucleocapsids are cross-banded, obliquely striated, and with rope-like features (depending on the negative staining method).

Virions composed of 5% nucleic acid.

Genome

Monopartite, linear, single stranded, positive sense RNA, 6300-7600 nucleotides long. The 3' terminus has a poly(A) tract. The 5' terminus probably has a methylated nucleotide cap.

Genus Genomic Organization

The genome is translated by means of 3 slightly overlapping ORFs. The largest ORF (ORF1) is probably involved in replication, while ORF2 (putative movement protein) and ORF3 (coat protein) are expressed from subgenomic mRNAs.

Type Member Genomic Organization

The genome is believed to be translated by means of three open reading frames:
  1. 216.5 kDa polyprotein: putative replicase
  2. 50.4 kDa Movement protein
  3. 21.4 kDa Coat protein