The nucleotide sequence of RNA1 of Lettuce big-vein virus, genus Varicosavirus, reveals its relation to nonsegmented negative-strand RNA viruses.
The complete nucleotide sequence of RNA1 from Lettuce big-vein virus (LBVV), the type member of the genus Varicosavirus, was determined. LBVV RNA1 consists of 6797 nucleotides and contains one large ORF that encodes a large (L) protein of 2040 amino acids with a predicted M(r) of 232,092. Northern blot hybridization analysis indicated that the LBVV RNA1 is a negative-sense RNA. Database searches showed that the amino acid sequence of L protein is homologous to those of L polymerases of nonsegmented negative-strand RNA viruses. A cluster dendrogram derived from alignments of the LBVV L protein and the L polymerases indicated that the L protein is most closely related to the L polymerases of plant rhabdoviruses. Transcription termination/polyadenylation signal-like poly(U) tracts that resemble those in rhabdovirus and paramyxovirus RNAs were present upstream and downstream of the coding region. Although LBVV is related to rhabdoviruses, a key distinguishing feature is that the genome of LBVV is segmented. The results reemphasize the need to reconsider the taxonomic position of varicosaviruses.
Sasaya
Takahide
T
National Agricultural Research Center for Western Region, Zentsuji Campus, Kagawa, Zentsuji, Japan. tsasaya@affrc.go.jp
Ishikawa
Koichi
K
Koganezawa
Hiroki
H
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases; D018545:Lactuca / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010942:Plant Viruses / Q000145:classification* / Q000235:genetics*; D012328:RNA Viruses / Q000145:classification / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics; D012209:Rhabdoviridae / Q000235:genetics; D014764:Viral Proteins
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D012367:RNA, Viral; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases