title: The genome of Beet cryptic virus 1 shows high homology to certain  cryptoviruses present in phylogenetically distant hosts.
abstract: This study determined the complete nucleotide sequence of Beet cryptic virus 1 (BCV1). As expected by analogy to previously sequenced alphacryptoviruses, dsRNA1 (2008 bp) encodes a 72.5-kDa protein containing sequence motifs characteristic for RNA-dependent RNA polymerases (RdRp). In addition to the full-length dsRNA1, a truncated form was also detected in dsRNA extracts. dsRNA2 (1783 bp) codes for the viral coat protein (CP) as proven by the identity of the predicted CP sequence to peptide sequences of the purified virion protein. The amino acid sequence of BCV1 RdRp as well as the 5'- and 3'-UTRs show 81-85% identity to the corresponding regions of Vicia cryptic virus (VCV), White clover cryptic virus 1 (WCCV1) and Carrot cryptic virus (CaCV). The amino acid sequence identity of the CP is about 55-62%, moreover, a strong conservation of predicted alpha-helical regions was observed. The high degree of similarity of these seed- and pollen-transmitted viruses persisting in phylogenetically distant hosts, together with their high similarity to fungal partitiviruses strongly supports the hypothesis that horizontal transfer by a fungus played a role in the emergence of the present cryptovirus species. The change in the distribution of cryptic viruses may also be due to human influence: While earlier BCV1 occurred frequently in sugar beet cultivars, it is very rare in cultivars currently used in agricultural practice and was detected in only one of the 28 cultivars investigated in our experiments.
  
  
  BACKGROUND
  The online version of this article (doi:10.1007/s11262-009-0432-4) contains supplementary material, which is available to authorized users.
authors.affiliation: Department of Plant Physiology and Plant Biochemistry, Corvinus University of Budapest, Ménesi út 44, 1118 Budapest, Hungary.
authors.forename: Anita
authors.initials: A
authors.lastname: Szego
authors.forename: Natalya
authors.initials: N
authors.lastname: Enünlü
authors.forename: Sachin D
authors.initials: SD
authors.lastname: Deshmukh
authors.forename: Dorina
authors.initials: D
authors.lastname: Veliceasa
authors.forename: Eva
authors.initials: E
authors.lastname: Hunyadi-Gulyás
authors.forename: Thomas
authors.initials: T
authors.lastname: Kühne
authors.forename: Pál
authors.initials: P
authors.lastname: Ilyés
authors.forename: László
authors.initials: L
authors.lastname: Potyondi
authors.forename: Katalin
authors.initials: K
authors.lastname: Medzihradszky
authors.forename: Noémi
authors.initials: N
authors.lastname: Lukács
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D027461:Beta vulgaris / Q000821:virology*; D036022:Capsid Proteins / Q000235:genetics; D016000:Cluster Analysis; D016679:Genome, Viral; D008969:Molecular Sequence Data; D010802:Phylogeny; D010942:Plant Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D017433:Protein Structure, Secondary; D012328:RNA Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D036022:Capsid Proteins; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase