The complete nucleotide sequence and genome organization of odontoglossum ringspot tobamovirus RNA

Summary The complete nucleotide sequence of the genomic RNA of odontoglossum ringspot tobamovirus (ORSV) was determined. The RNA genome of ORSV is 6618 nucleotides long and contains five open reading frames (ORFs 1 to 5) coding for proteins of Mr 126 K, 181 K, 34 K, 18 K and 52 K, respectively. This is the longest RNA of the known viruses of theTobamovirus genus. The sequences of the ORSV RNA encoded proteins exhibit high homology to the proteins of the members of theTobamovirus genus. The genomic organization and sequence analysis showed that ORSV is more closely related to tobacco mild green mosaic virus (TMGMV), pepper mild mottle virus (PMMV), tomato mosaic virus (ToMV) and TMV than to cucumber green mottle mosaic virus (CGMMV) and sunn-hemp mosaic virus (SHMV).The nucleotide sequence reported in this paper will appear in the EMBL, GenBank and DDBJ nucleotide sequence databases under the accession number X82130.     

The complete genome sequence of shope (rabbit) fibroma virus

We have determined the complete DNA sequence of the Leporipoxvirus Shope fibroma virus (SFV). The SFV genome spans 159.8 kb and encodes 165 putative genes of which 13 are duplicated in the 12.4-kb terminal inverted repeats. Although most SFV genes have homologs encoded by other Chordopoxvirinae, the SFV genome lacks a key gene required for the production of extracellular enveloped virus. SFV also encodes only the smaller ribonucleotide reductase subunit and has a limited nucleotide biosynthetic capacity. SFV preserves the Chordopoxvirinae gene order from S012L near the left end of the chromosome through to S142R (homologs of vaccinia F2L and B1R, respectively). The unique right end of SFV appears to be genetically unstable because when the sequence is compared with that of myxoma virus, five myxoma homologs have been deleted (C. Cameron, S. Hota-Mitchell, L. Chen, J. Barrett, J.-X. Cao, C. Macaulay, D. Willer, D. Evans, and G. McFadden, 1999, Virology 264, 298-318). Most other differences between these two Leporipoxviruses are located in the telomeres. Leporipoxviruses encode several genes not found in other poxviruses including four small hydrophobic proteins of unknown function (S023R, S119L, S125R, and S132L), an alpha 2, 3-sialyltransferase (S143R), a protein belonging to the Ig-like protein superfamily (S141R), and a protein resembling the DNA-binding domain of proteins belonging to the HIN-200 protein family S013L). SFV also encodes a type II DNA photolyase (S127L). Melanoplus sanguinipes entomopoxvirus encodes a similar protein, but SFV is the first mammalian virus potentially capable of photoreactivating ultraviolet DNA damage.     

The complete nucleotide sequence and genome organization of a novel carmovirus--honeysuckle ringspot virus isolated from honeysuckle

A virus associated with yellow-to-purple ringspot on honeysuckle plants has been detected and tentatively named honeysuckle ringspot virus (HnRSV). The complete nucleotide sequence of HnRSV from infected honeysuckle has been determined. The genomic RNA of HnRSV is 3,956 nucleotides in length and is predicted to contain five open reading frames (ORFs). Comparisons of the amino acid sequences of the ORFs of HnRSV with those of members of the family Tombusviridae show that HnRSV is closely related to members of the genus Carmovirus. Phylogenetic analysis based on the amino acid sequences of RdRp and coat protein and nucleotide sequences of the whole genome revealed that HnRSV forms a subgroup with the carmoviruses. Together, our results support the classification of HnRSV as a member of a new species in the genus Carmovirus, family Tombusviridae.     

The complete genome sequence of Lamium mild mosaic virus, a member of the genus Fabavirus

Lamium mild mosaic virus (LMMV) is the only one of the five members of the genus Fabavirus for which there are no nucleotide sequence data. In this study, the complete genome sequence of LMMV was determined and compared with the available complete genome sequences of other members of the genus Fabavirus. The genome was the largest of the genus but maintained the typical organization, with RNA 1 of 6080 nucleotides (nt), RNA 2 of 4065 nt, and an unusually long 3′ untranslated region in RNA 2 of 603 nt. Phylogenetic analysis of the amino acid sequences of the protease-polymerase (Pro-Pol) region and the two coat proteins confirmed that LMMV belongs to a distinct species within the genus Fabavirus.     

The complete genome sequence of Piper yellow mottle virus (PYMoV)

This study reports the first complete genome sequence of Piper yellow mottle virus (PYMoV, KC808712) identified in black pepper. The genome is 7,622 nucleotides long, possessing four open reading frames (ORFs). ORF1, ORF2 and ORF4 of PYMoV are reported as hypothetical proteins of unknown function with a predicted molecular mass of 15.7, 17.1 and 17.9 kDa, respectively. ORF3 of PYMoV encodes a polyprotein of 218.6 kDa and consists of a viral movement protein (MP), trimeric dUTPase, zinc finger, retropepsin, RT-LTR, and RNAse H. Detailed PYMoV genome analysis confirmed that it is a member of the family Caulimoviridae, genus Badnavirus. Fragments of two additional novel sequences resembling those found in members of the family Caulimoviridae were also identified in the black pepper sample, and the viruses from which they were derived were tentatively named Piper DNA virus 1 and 2.     

Complete genome sequence of switchgrass mosaic virus, a member of a proposed new species in the genus Marafivirus

The complete genome sequence of a virus recently detected in switchgrass (Panicum virgatum) was determined and found to be closely related to that of maize rayado fino virus (MRFV), genus Marafivirus, family Tymoviridae. The genomic RNA is 6408 nucleotides long. It contains three predicted open reading frames (ORFs 1-3), encoding proteins of 227?kDa, 43.9?kDa, and 31.5?kDa, compared to two ORFs (1 and 2) for MRFV. The complete genome shares 76?% sequence identity with MRFV. The nucleotide sequence of ORF2 of this virus and the amino acid sequence of its encoded protein are 49?% and 77?% identical, respectively, to those of MRFV. The virus-encoded polyprotein and capsid protein aa sequences are 83?% and 74-80?% identical, respectively, to those of MRFV. Although closely related to MRFV, the amino acid sequence of its capsid protein (CP) forms a clade that is separate from that of MRFV. Based on the International Committee on Taxonomy of Viruses (ICTV) sequence-related criteria for delineation of species within the genus Marafivirus, the virus qualifies as a member of a new species, and the name Switchgrass mosaic virus (SwMV) is proposed.     

Tomato chocolate spot virus, a member of a new torradovirus species that causes a necrosis-associated disease of tomato in Guatemala

Tomatoes in Guatemala have been affected by a new disease, locally known as “mancha de chocolate” (chocolate spot). The disease is characterized by distinct necrotic spots on leaves, stems and petioles that eventually expand and cause a dieback of apical tissues. Samples from symptomatic plants tested negative for infection by tomato spotted wilt virus, tobacco streak virus, tobacco etch virus and other known tomato-infecting viruses. A virus-like agent was sap-transmitted from diseased tissue to Nicotiana benthamiana and, when graft-transmitted to tomato, this agent induced chocolate spot symptoms. This virus-like agent also was sap-transmitted to Datura stramonium and Nicotiana glutinosa, but not to a range of non-solanaceous indicator plants. Icosahedral virions ~28–30 nm in diameter were purified from symptomatic N. benthamiana plants. When rub-inoculated onto leaves of N. benthamiana plants, these virions induced symptoms indistinguishable from those in N. benthamiana plants infected with the sap-transmissible virus associated with chocolate spot disease. Tomatoes inoculated with sap or grafted with shoots from N. benthamiana plants infected with purified virions developed typical chocolate spot symptoms, consistent with this virus being the causal agent of the disease. Analysis of nucleic acids associated with purified virions of the chocolate-spot-associated virus, revealed a genome composed of two single-stranded RNAs of ~7.5 and ~5.1 kb. Sequence analysis of these RNAs revealed a genome organization similar to recently described torradoviruses, a new group of picorna-like viruses causing necrosis-associated diseases of tomatoes in Europe [tomato torrado virus (ToTV)] and Mexico [tomato apex necrosis virus (ToANV) and tomato marchitez virus (ToMarV)]. Thus, the ~7.5 kb and ~5.1 kb RNAs of the chocolate-spot-associated virus corresponded to the torradovirus RNA1 and RNA2, respectively; however, sequence comparisons revealed 64–83% identities with RNA1 and RNA2 sequences of ToTV, ToANV and ToMarV. Together, these results indicate that the chocolate-spot-associated virus is a member of a distinct torradovirus species and, thus, another member of the recently established genus Torradovirus in the family Secoviridae. The name tomato chocolate spot virus is proposed.     

The complete genome sequence of polygonum ringspot virus

The complete genome sequence of polygonum ringspot virus (PolRSV), genus Tospovirus, family Bunyaviridae, was determined. This is the first report of the complete genome sequence for a European tospovirus isolate. The large RNA of PolRSV was 8893 nucleotides (nt) in size and contained a single open reading frame of 8628 nucleotides in the viral-complementary sense, coding for a predicted RNA-dependent RNA polymerase of 330.9 kDa. Two untranslated regions of 230 and 32 nucleotides were present at the 5′ and 3′ termini, respectively, which showed conserved terminal sequences, as commonly observed for tospovirus genomic RNAs. The medium and small (S) RNAs were 4710 and 2485 nucleotides in size, respectively, and showed 99 % homology to the corresponding genomic segment of a previously partially characterized PolRSV isolate, Plg3. Protein sequences for G_N/G_C, N and NSs were identical in length in the two PolRSV isolates, while an amino acid insertion was observed for the NSm protein of the newly characterized isolate. The noncoding intergenic region of the S RNA was very short (183 nt) and was not predicted to form a hairpin structure, confirming that this unique characteristic within tospoviruses, previously observed for Plg3, is not isolate specific.     

The complete genome sequence and genome structure of frangipani mosaic virus

In this study, the complete sequence of the genomic RNA of frangipani mosaic virus (FrMV) has been determined and compared to those of other known tobamoviruses. The complete genome sequence of FrMV consisted of 6,643 nucleotides. The FrMV genomic RNA encoded four open reading frames (ORFs), for proteins of M(r) 128 kDa (1,147 aa), 186 kDa (1,651 aa), 30 kDa (257 aa) and 18 kDa (175 aa) from the 5′ to the 3′ end. Overall similarities for the four ORFs of FrMV-P ranged from 26.8 to 53.0% at the amino acid level when compared to those of 24 other tobamoviruses. Phylogenetic analysis of the FrMV replicase (186 kDa) and MP revealed that FrMV is closely related to SHMV and CMMoV, while the FrMV replicase (128 kDa) is more closely related to cucurbit-infecting and malvaceous-infecting tobamoviruses, and the FrMV CP is closely related to that of CMMoV and solanaceous-infecting tobamoviruses.     

Complete sequence and genome structure of cactus mild mottle virus

We have completed the genomic sequence of a tobamovirus, cactus mild mottle virus (CMMoV), and compared it to those of other known tobamoviruses. The complete genome sequence of CMMoV consists of 6,449 nucleotides. The genome RNA of the virus contains four open reading frames, encoding, from the 5′ to the 3′ end, the 120-kDa viral replicase, the 186-kDa viral polymerase, the 33-kDa movement protein and the 18-kDa coat protein. Overall amino acid similarities for the four viral proteins of CMMoV ranged from 16.3 to 44.4% compared to those of 20 other tobamoviruses. Phylogenetic analysis of the viral replicases and MP revealed that CMMoV is closely related to cucurbit-infecting tobamoviruses, while the CMMoV CP is more closely related to brassica- and solanaceous-infecting tobamoviruses. B. E. Min and Y. S. Song contributed equally in this study.     

The complete genome sequence of Canna yellow streak virus

Canna yellow streak virus (Potyvirus, Potyviridae) was sequenced using the novel method of next-generation pyrosequencing. The complete genome was found to be 9,502 nucleotides excluding the poly-A tail with a predicted genome organisation typical for a member of the genus Potyvirus. As with other potyviruses that infect monocotyledons, some of the predicted cleavage sites of the polyprotein genome were unusual, such as a glutamic acid/threonine (E/T) between the CI and 6K2 proteins and a glutamic acid/aspartic acid (E/D) between the NIa and NIb proteins. Evidence of the presence of endogenous pararetroviruses in the canna genome was found from the large number of sequences obtained with this method.     

The complete genome sequence and genome structure of passion fruit mosaic virus

In this study, we determined the complete sequence of the genomic RNA of a Florida isolate of maracuja mosaic virus (MarMV-FL) and compared it to that of a Peru isolate of the virus (MarMV-P) and those of other known tobamoviruses. Complete sequence analysis revealed that the isolate should be considered a member of a new species and named passion fruit mosaic virus (PafMV). The genomic RNA of PafMV consists of 6,791 nucleotides and encodes four open reading frames (ORFs) coding for proteins of 125 kDa (1,101 aa), 184 kDa (1,612 aa), 34 kDa (311 aa) and 18 kDa (164 aa) in consecutive order from the 5’ to the 3’ end. The sequence homologies of the four ORFs of PafMV were from 78.8% to 81.6% to those of MarMV-P at the amino acid level. The sequence homologies of the four ORFs of PafMV ranged from 36.0% to 77.9% and from 21.7% to 81.6% to those of other tobamoviruses, at the nucleotide and amino acid level, respectively. Phylogenetic analysis revealed that these PafMV-encoded proteins are closely related to those of MarMV-P. In conclusion, the results indicate that PafMV and MarMV-P belong to different species within the genus Tobamovirus.     

The complete genome sequence of a virus associated with cotton blue disease, cotton leafroll dwarf virus, confirms that it is a new member of the genus Polerovirus

Cotton blue disease is the most important virus disease of cotton in the southern part of America. The complete nucleotide sequence of the ssRNA genome of the cotton blue disease-associated virus was determined for the first time. It comprised 5,866 nucleotides, and the deduced genomic organization resembled that of members of the genus Polerovirus. Sequence homology comparison and phylogenetic analysis confirm that this virus (previous proposed name cotton leafroll dwarf virus) is a member of a new species within the genus Polerovirus.     

The complete genome sequence of New World jatropha mosaic virus

Full-length sequences of a bipartite begomovirus were obtained from a plant of Jatropha multifida in Florida showing symptoms of foliar mosaic, distortion and necrosis. Sequences of four clones each of a DNA-A and DNA-B were obtained, which showed very low sequence diversity among themselves. The clones were infectious when biolistically inoculated to J. multifida, Phaseolus vulgaris and Nicotiana tabacum, but not to J. curcas. The DNA-A sequences had less than 89 % pairwise identity scores with the DNA-A of other begomoviruses. The DNA-A appeared to be a recombinant in that 18 % of the DNA-A (470 nt) had a pairwise identity score of 91.98 % with RhRGMV, indicating that this portion most likely originated from a virus closely related to RhRGMV. The remaining 82 % of the DNA-A had lower identity scores with TbMoLCV (87.84 %) and RhRGMV (87.46 %), which suggests that this part of the component originated from an undescribed virus. There was no evidence for recombination in the DNA-B. Equivalent sequences of the DNA-A had the highest identity score (94.18 %) with a 533-nt sequence obtained from J. multifida from Puerto Rico in 2001 (GenBank accession no. AF058025). Pairwise comparison, recombination and phylogenetic analysis, and biology suggest that these clones are those of jatropha mosaic virus first reported from Puerto Rico. This is the first report of the complete genome sequence of jatropha mosaic virus.     

The complete nucleotide sequence of the genomic RNA of the tobamovirus tobacco mild green mosaic virus

The complete nucleotide sequence of the genomic RNA of the tobamovirus tobacco mild green mosaic virus (TM-GMV) was determined. It shows 64.4% sequence homology with the genomic RNA of tobacco mosaic virus (TMV) and 66.0% with that of tomato mosaic virus (ToMV). Its genomic organization is similar to that of TMV and ToMV. The 5' proximal open reading frame (ORF) encodes a 126K polypeptide and a 183K readthrough product in which nucleotide-binding and polymerase-sequence motifs are found. The third ORF encodes a 28.5K protein homologous to TMV and ToMV movement proteins. A conserved core is found with four other tobamoviruses and two tobraviruses suggesting a common mechanism of cell-to-cell movement for tobamo- and tobraviruses. The fourth ORF encodes the 17.5K coat protein. Homology between the RNAs of TMGMV and its satellite virus STMV is limited to their 3' termini, and structural comparisons suggest that this region may determine the nature of the satellite/helper virus interaction.     

First genome sequence of St. Louis encephalitis virus (SLEV) isolated from a human in Brazil

St. Louis encephalitis virus (SLEV), a member of the family Flaviviridae, genus Flavivirus, is a causative agent of encephalitis in the Americas. In Brazil, sporadic cases of SLEV infection have been reported since 1953, but the first outbreak of SLEV in Brazil was identified only in 2007, concomitant with an outbreak of dengue virus (DENV) serotype 3. This finding, along with other reports, indicates that SLEV circulation in Brazil is largely unknown, and there may be epidemiological implications of the co-circulation of SLEV, DENV and other flaviviruses in Brazil. Here, we describe the first complete genome sequence of an SLEV strain isolated from a human patient in Brazil, strain BeH 355964. Phylogenetic analysis was performed to determine the genotype of BeH 355964 using the full-length genome and envelope (E) gene sequences separately. Both analyses showed that BeH 355964 could be classified as genotype V. Although the number of single gene sequences available is greater (such as for the E gene), the phylogenetic tree based on the complete genome sequence was better supported and provided further information about the virus.