title: Codon usage, amino acid usage, transfer RNA and amino-acyl-tRNA synthetases in Mimiviruses.
abstract: Mimiviruses are giant viruses that infect phagocytic protists, including Acanthamoebae spp., which were discovered during the past decade. They are the current record holder among viruses for their large particle and genome sizes. One group is composed of three lineages, referred to as A, B and C, which include the vast majority of the Mimiviridae members. Cafeteria roenbergensis virus represents a second group, though the Mimiviridae family is still expanding. We analyzed the codon and amino acid usages in mimiviruses, as well as both the transfer RNA (tRNA) and amino acyl-tRNA synthetases. We confirmed that the codon and amino acid usages of these giant viruses are highly dissimilar to those in their amoebal host Acanthamoeba castellanii and are instead correlated with the high adenine and thymine (AT) content of Mimivirus genomes. We further describe that the set of tRNAs and amino acyl-tRNA synthetases in mimiviruses is globally not adapted to the codon and amino acid usages of these viruses. Notwithstanding, Leu(TAA)tRNA, present in several Mimivirus genomes and in multiple copies in some viral genomes, may complement the amoebal tRNA pool and may contribute to accommodate the viral AT-rich codons. In addition, we found that the genes most highly expressed at the beginning of the Mimivirus replicative cycle have a nucleotide content more adapted to the codon usage in A.castellanii.
authors.affiliation: URMITE UM3, CNRS 7278, IRD 198, INSERM U1905, Institut Hospitalo-Universitaire Méditerranée Infection, Facultés de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Colson
authors.forename: Ghislain
authors.initials: G
authors.lastname: Fournous
authors.forename: Seydina M
authors.initials: SM
authors.lastname: Diene
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D048248:Acanthamoeba castellanii; D000596:Amino Acids / Q000235:genetics*; D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D003062:Codon; D019295:Computational Biology / Q000379:methods; D005814:Genes, Viral; D056686:Mimiviridae / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D058009:Stramenopiles
chemical_list: D000596:Amino Acids; D003062:Codon; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases