The 1.2-megabase genome sequence of Mimivirus.
We recently reported the discovery and preliminary characterization of Mimivirus, the largest known virus, with a 400-nanometer particle size comparable to mycoplasma. Mimivirus is a double-stranded DNA virus growing in amoebae. We now present its 1,181,404-base pair genome sequence, consisting of 1262 putative open reading frames, 10% of which exhibit a similarity to proteins of known functions. In addition to exceptional genome size, Mimivirus exhibits many features that distinguish it from other nucleocytoplasmic large DNA viruses. The most unexpected is the presence of numerous genes encoding central protein-translation components, including four amino-acyl transfer RNA synthetases, peptide release factor 1, translation elongation factor EF-TU, and translation initiation factor 1. The genome also exhibits six tRNAs. Other notable features include the presence of both type I and type II topoisomerases, components of all DNA repair pathways, many polysaccharide synthesis enzymes, and one intein-containing gene. The size and complexity of the Mimivirus genome challenge the established frontier between viruses and parasitic cellular organisms. This new sequence data might help shed a new light on the origin of DNA viruses and their role in the early evolution of eukaryotes.
Unité des Rickettsies, Faculté de Médecine, CNRS UMR6020, Université de la Méditerranée, 13385 Marseille Cedex 05, France. Didier.Raoult@medecine.univ-mrs.fr
Didier
D
Raoult
Stéphane
S
Audic
Catherine
C
Robert
Chantal
C
Abergel
Patricia
P
Renesto
Hiroyuki
H
Ogata
Bernard
B
La Scola
Marie
M
Suzan
Jean-Michel
JM
Claverie
D000048:Acanthamoeba / Q000821:virology; D000818:Animals; D001482:Base Composition; D019295:Computational Biology; D004260:DNA Repair / Q000235:genetics; D026942:DNA Topoisomerases / Q000235:genetics; D004267:DNA Viruses / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D004798:Enzymes / Q000235:genetics / Q000378:metabolism; D005814:Genes, Viral; D016679:Genome, Viral; D047668:Inteins; D007438:Introns; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D014176:Protein Biosynthesis; D017510:Protein Folding; D020543:Proteome; D012343:RNA, Transfer / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D004279:DNA, Viral; D004798:Enzymes; D020543:Proteome; D012367:RNA, Viral; D014764:Viral Proteins; D012343:RNA, Transfer; D026942:DNA Topoisomerases