Euprosterna elaeasa virus genome sequence and evolution of the Tetraviridae family: emergence of bipartite genomes and conservation of the VPg signal with the dsRNA Birnaviridae family.
The Tetraviridae is a family of non-enveloped positive-stranded RNA insect viruses that is defined by the T=4 symmetry of virions. We report the complete Euprosterna elaeasa virus (EeV) genome sequence of 5698 nt with no poly(A) tail and two overlapping open reading frames, encoding the replicase and capsid precursor, with approximately 67% amino acid identity to Thosea asigna virus (TaV). The N-terminally positioned 17 kDa protein is released from the capsid precursor by a NPGP motif. EeV has 40 nm non-enveloped isometric particles composed of 58 and 7 kDa proteins. The 3'-end of TaV/EeV is predicted to form a conserved pseudoknot. Replicases of TaV and EeV include a newly delineated VPg signal mediating the protein priming of RNA synthesis in dsRNA Birnaviridae. Results of rooted phylogenetic analysis of replicase and capsid proteins are presented to implicate recombination between monopartite tetraviruses, involving autonomization of a sgRNA, in the emergence of bipartite tetraviruses. They are also used to revise the Tetraviridae taxonomy.
Zeddam
Jean-Louis
JL
IRD, UR 072, Laboratoire Evolution, Génomes et Spéciation, UPR 9034, CNRS, 91198 Gif-sur-Yvette Cedex, France.
Gordon
Karl H J
KH
Lauber
Chris
C
Alves
Cristiano A Felipe
CA
Luke
Brian T
BT
Hanzlik
Terry N
TN
Ward
Vernon K
VK
Gorbalenya
Alexander E
AE
D000818:Animals; D036022:Capsid Proteins / Q000235:genetics; D016000:Cluster Analysis; D019143:Evolution, Molecular; D016679:Genome, Viral; D007313:Insecta / Q000821:virology*; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D012328:RNA Viruses / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D026801:Synteny; D014771:Virion / Q000648:ultrastructure
D036022:Capsid Proteins; D011498:Protein Precursors; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase