RESUMO
The family of giant viruses is still expanding, and evidence of a translational machinery is emerging in the virosphere. The Klosneuvirinae group of giant viruses was first reconstructed from in silico studies, and then a unique member was isolated, Bodo saltans virus. Here we describe the isolation of a new member in this group using coculture with the free-living amoeba Vermamoeba vermiformis This giant virus, called Yasminevirus, has a 2.1-Mb linear double-stranded DNA genome encoding 1,541 candidate proteins, with a GC content estimated at 40.2%. Yasminevirus possesses a nearly complete translational machinery, with a set of 70 tRNAs associated with 45 codons and recognizing 20 amino acids (aa), 20 aminoacyl-tRNA synthetases (aaRSs) recognizing 20 aa, as well as several translation factors and elongation factors. At the genome scale, evolutionary analyses placed this virus in the Klosneuvirinae group of giant viruses. Rhizome analysis demonstrated that the genome of Yasminevirus is mosaic, with â¼34% of genes having their closest homologues in other viruses, followed by â¼13.2% in Eukaryota, â¼7.2% in Bacteria, and less than 1% in Archaea Among giant virus sequences, Yasminevirus shared 87% of viral hits with Klosneuvirinae. This description of Yasminevirus sheds light on the Klosneuvirinae group in a captivating quest to understand the evolution and diversity of giant viruses.IMPORTANCE Yasminevirus is an icosahedral double-stranded DNA virus isolated from sewage water by amoeba coculture. Here its structure and replicative cycle in the amoeba Vermamoeba vermiformis are described and genomic and evolutionary studies are reported. This virus belongs to the Klosneuvirinae group of giant viruses, representing the second isolated and cultivated giant virus in this group, and is the first isolated using a coculture procedure. Extended translational machinery pointed to Yasminevirus among the quasiautonomous giant viruses with the most complete translational apparatus of the known virosphere.
Assuntos
DNA Viral/genética , Regulação Viral da Expressão Gênica , Genoma Viral , Vírus Gigantes/genética , Mimiviridae/genética , Vírion/genética , Aminoácidos/genética , Aminoácidos/metabolismo , Aminoacil-tRNA Sintetases/classificação , Aminoacil-tRNA Sintetases/genética , Aminoacil-tRNA Sintetases/metabolismo , Composição de Bases , Mapeamento Cromossômico , Técnicas de Cocultura , Códon/química , Códon/metabolismo , DNA Viral/metabolismo , Tamanho do Genoma , Vírus Gigantes/classificação , Vírus Gigantes/metabolismo , Vírus Gigantes/ultraestrutura , Hartmannella/virologia , Mimiviridae/classificação , Mimiviridae/metabolismo , Mimiviridae/ultraestrutura , Fatores de Alongamento de Peptídeos/classificação , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Filogenia , Biossíntese de Proteínas , RNA de Transferência/classificação , RNA de Transferência/genética , RNA de Transferência/metabolismo , Análise de Sequência de DNA , Vírion/metabolismo , Vírion/ultraestruturaRESUMO
Free-living amoebae are protists that are widely distributed in the environment including water, soil, and air. Although the amoebae of the genus Acanthamoeba are still the most studied, other species, such as Vermamoeba vermiformis (formerly Hartmannella vermiformis), are the subject of increased interest. Found in natural or man-made aquatic environments, V. vermiformis can support the multiplication of other microorganisms and is able to harbor and potentially protect pathogenic bacteria or viruses. This feature is to be noted because of the presence of this thermotolerant amoeba in hospital water networks. As a consequence, this protist could be implicated in health concerns and be indirectly responsible for healthcare-related infections. This review highlights, among others, the consequences of V. vermiformis relationships with other microorganisms and shows that this free-living amoeba species is therefore of interest for public health.
