The Picornavirales are an order of virus

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es with vertebrate

Vertebrate

Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

, insects and plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 hosts.
This group consists of viruses which have (+) sense single stranded RNA genomes.

Five families within this group - Caliciviridae, Dicistroviridae, Picornaviridae, Potyviridae and Sequiviridae share a number of common features:

conserved RNA-dependent RNA polymerase

genome has a protein attached to the 5' end

no overlapping open reading frames within the genome

all the RNAs are translated into a polyprotein before processing

It has been suggested that the evolution of these viruses may have preceded the separation of eukaryote

Eukaryote

A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...

s into the extant crown groups.

External links

• ICTV Virus Taxonomy 2009 http://www.ictvonline.org
• UniProt Taxonomy http://www.uniprot.org/taxonomy/675063