RESUMO
Linear viruses with double-stranded DNA genomes are classified into two families, Lipothrixviridae and Rudiviridae. The members of these two families, all of which infect hyperhermophilic members of the domain Archaea, differ significantly in the complexity of their virions as well as in their mechanisms of genome replication. However, recent structural and genomic studies have revealed a robust evolutionary link between members of the two families. To acknowledge this relationship we propose to unify the two families into the new taxonomic order "Ligamenvirales".
Assuntos
Archaea/virologia , Lipothrixviridae/classificação , Rudiviridae/classificação , Sequência de Aminoácidos , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Análise por Conglomerados , DNA/genética , DNA Viral/genética , Ordem dos Genes , Genoma Viral , Lipothrixviridae/genética , Lipothrixviridae/crescimento & desenvolvimento , Microscopia Eletrônica de Transmissão , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Estrutura Terciária de Proteína , Rudiviridae/genética , Rudiviridae/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Vírion/ultraestrutura , Replicação ViralRESUMO
Bacteriophages are classified into one order and 13 families. Over 5100 phages have been examined in the electron microscope since 1959. At least 4950 phages (96%) are tailed. They constitute the order Caudovirales and three families. Siphoviridae or phages with long, noncontractile tails predominate (61% of tailed phages). Polyhedral, filamentous, and pleomorphic phages comprise less than 4% of bacterial viruses. Bacteriophages occur in over 140 bacterial or archaeal genera. Their distribution reflects their origin and bacterial phylogeny. Bacteriophages are polyphyletic, arose repeatedly in different hosts, and constitute 11 lines of descent. Tailed phages appear as monophyletic and as the oldest known virus group.
