title: Giant viruses with an expanded complement of translation system components.
abstract: The discovery of giant viruses blurred the sharp division between viruses and cellular life. Giant virus genomes encode proteins considered as signatures of cellular organisms, particularly translation system components, prompting hypotheses that these viruses derived from a fourth domain of cellular life. Here we report the discovery of a group of giant viruses (Klosneuviruses) in metagenomic data. Compared with other giant viruses, the Klosneuviruses encode an expanded translation machinery, including aminoacyl transfer RNA synthetases with specificities for all 20 amino acids. Notwithstanding the prevalence of translation system components, comprehensive phylogenomic analysis of these genes indicates that Klosneuviruses did not evolve from a cellular ancestor but rather are derived from a much smaller virus through extensive gain of host genes.
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA. fschulz@lbl.gov koonin@ncbi.nlm.nih.gov twoyke@lbl.gov.
authors.forename: Frederik
authors.identifier: 0000-0002-4932-4677
authors.initials: F
authors.lastname: Schulz
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
authors.forename: Natalya
authors.identifier: 0000-0002-3633-5123
authors.initials: N
authors.lastname: Yutin
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
authors.forename: Natalia N
authors.identifier: 0000-0002-5802-9485
authors.initials: NN
authors.lastname: Ivanova
authors.affiliation: Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Davi R
authors.initials: DR
authors.lastname: Ortega
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, "Chemistry Meets Microbiology" Research Network, University of Vienna, 1090 Vienna, Austria.
authors.forename: Tae Kwon
authors.identifier: 0000-0003-3845-7316
authors.initials: TK
authors.lastname: Lee
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, "Chemistry Meets Microbiology" Research Network, University of Vienna, 1090 Vienna, Austria.
authors.forename: Julia
authors.identifier: 0000-0002-9764-7534
authors.initials: J
authors.lastname: Vierheilig
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, "Chemistry Meets Microbiology" Research Network, University of Vienna, 1090 Vienna, Austria.
authors.forename: Holger
authors.identifier: 0000-0002-4195-0913
authors.initials: H
authors.lastname: Daims
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, "Chemistry Meets Microbiology" Research Network, University of Vienna, 1090 Vienna, Austria.
authors.forename: Matthias
authors.identifier: 0000-0002-8309-5855
authors.initials: M
authors.lastname: Horn
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, "Chemistry Meets Microbiology" Research Network, University of Vienna, 1090 Vienna, Austria.
authors.forename: Michael
authors.identifier: 0000-0002-9778-7684
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA.|Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Grant J
authors.identifier: 0000-0003-1556-4864
authors.initials: GJ
authors.lastname: Jensen
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
authors.forename: Nikos C
authors.identifier: 0000-0002-6131-0462
authors.initials: NC
authors.lastname: Kyrpides
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA. fschulz@lbl.gov koonin@ncbi.nlm.nih.gov twoyke@lbl.gov.
authors.forename: Eugene V
authors.identifier: 0000-0003-3943-8299
authors.initials: EV
authors.lastname: Koonin
authors.affiliation: Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA. fschulz@lbl.gov koonin@ncbi.nlm.nih.gov twoyke@lbl.gov.
authors.forename: Tanja
authors.identifier: 0000-0002-9485-5637
authors.initials: T
authors.lastname: Woyke
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics*; D001317:Austria; D016679:Genome, Viral; D000072139:Giant Viruses / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D056186:Metagenomics; D010802:Phylogeny; D014176:Protein Biosynthesis / Q000235:genetics*; D062065:Wastewater / Q000821:virology
chemical_list: D000604:Amino Acyl-tRNA Synthetases; D062065:Wastewater