From MicrobeWiki, the student-edited microbiology resource
Revision as of 14:40, 27 June 2006 by Chochu444 (talk | contribs) (Genome Structure)
Jump to: navigation, search

Baltimore Classification

Higher order taxa

Viruses; ssRNA positive-strand viruses, no DNA stage; Tobamovirus


Cucumber green mottle mosaic virus, Frangipani mosaic virus (examples)

Description and Significance

Genome Structure

The genome of Tobamovirus is usually monomeric or polymeric, not segmented, and contains a single molecule of linear, positive-sense, single-stranded RNA. Minor species of non-genomic nucleic acid may also be found in virions. The encapsidated nucleic acid is mainly of genomic origin but virions may also contain nucleic acid of host origin and subgenomic mRNA including host rRNA found in the short particles of some species. The genome is sequenced and the complete sequence is about 6450 nucleotides long. The genome has a base ratio of 23-24.32-25.8 % guanine; 24.6-27.92-29.8 % adenine; 18-19.02-20.6 % cytosine; 26.3-28.72-31.6 % uracil. The 5'-end of the genome has a methylated nucleotide cap and the cap sequence type is m7G5'ppp5 ('Gp). The 3'-terminus has a tRNA-like structure that accepts histidine.

Virion Structure of a Tobamovirus

Reproduction Cycle of a Tobamovirus in a Host Cell

Viral Ecology & Pathology