The complete nucleotide sequence of bean yellow mosaic potyvirus RNA

Summary The complete nucleotide sequence of an Australian strain of bean yellow mosaic virus (BYMV-S) has been determined from cloned viral cDNAs. The BYMV-S genome is 9 547 nucleotides in length excluding a poly(A) tail. Computer analysis of the sequence revealed a single long open reading frame (ORF) of 9 168 nucleotides, commencing at position 206 and terminating with UAG at position 9 374–6. The ORF potentially encodes a polyprotein of 3 056 amino acids with a deduced Mr of 347 409. The 5 and 3 untranslated regions are 205 and 174 nucleotides in length respectively. Alignment of the amino acid sequence of the BYMV-S polyprotein with those of other potyviruses identified nine putative proteolytic cleavage sites. The predicted consensus cleavage site of the BYMV NIa protease was found to differ from that described for other potyviruses. Processing of the BYMV polyprotein at the designated proteolytic cleavage sites would result in a typical potyviral genome arrangement. The amino acid sequences of the putative BYMV encoded proteins were compared to the homologous gene products of twelve individual potyviruses to identify overall and specific regions of amino acid sequence homology.The nucleotide sequence data reported in this paper has been submitted to GenBank nucleotide sequence database and has been assigned the accession number U47033.     

Nucleotide sequence of the 3' terminal region of plum pox potyvirus RNA

The nucleotide sequence of the 3' terminal 2854 nucleotides of plum pox virus RNA has been determined. There is an open reading frame of 2634 nucleotides upstream from a 220 nucleotide 3' non-coding region followed by a long poly(A) tail. The gene coding for the capsid protein has been mapped adjacent to the 3' non-coding region. The predicted capsid protein is originated by a Gln-Ala cleavage and consists of 330 amino acids; the central and carboxy terminal, but not the amino terminal regions present high sequence similarity with other potyviral capsid proteins. A truncated capsid protein which is present in purified preparations of plum pox virus is originated by a Gln-Thr cleavage and contains the 260 carboxy terminal amino acids of the capsid protein. The predicted plum pox virus RNA-dependent RNA polymerase, 518 amino acids long, has been localized at the 5' end of the open reading frame.     

Nucleotide sequence of the putative replicase gene of the sour cherry strain of plum pox potyvirus

Summary.  The complete nucleotide sequence of the NIb coding region of the sour cherry strain of plum pox potyvirus (PPV-SoC) has been determined. It consists of 1554 nucleotides and encodes a putative replicase protein of 518 amino acids. Sequence identity scores between NIb of PPV-SoC and other isolates of PPV are significantly low (c. 78%). Many of the nucleotide substitutions, however, are silent. PPV-SoC differs from isolates of PPV-D, PPV-M and PPV-El Amar at multiple amino acid positions that are conserved between the other isolates. The NIb sequence extends the PPV-SoC sequence presently available to 2781 nt from the 3′ end (∼ 28% of the genome). Received March 16, 1998 Accepted{June 10, 1998     

Comparative sequence analysis of four complete primary structures of plum pox virus strains

The complete nucleotide sequence of plum pox virus (PPV) strain SK 68 was determined from a series of overlapping cDNA clones. The exact 5 terminus was determined by direct RNA sequencing. The RNA sequence was 9786 nucleotides in length, excluding a 3 terminal poly(A) sequence. The large open reading frame starts at nucleotide position 147 and is terminated at position 9568. Comparison of cistrons from other plum pox virus strains with those predicted for the SK 68 strain indicated the same genomic organizations. Comparison of sequences leads to the following conclusions: (1) The genetic organization of all four PPV strains is identical, containing one large polyprotein gene and two noncoding regions at the 5 and 3 ends; (2) pairwise comparison of the genomic sequence of PPV SK 68 with other PPV strains shows 11% alteration. Sequence differences among strains are spread in a uniform manner upon the genome, except for the P1, HC-pro, and two noncoding regions, which are more conserved (with a 4% and 6.6% change). The stability of the noncoding regions is probably linked to their role in replication. The sequence variation has little effect on the amino acid sequence of the corresponding polypeptides, as changes occur preferentially in the third position of the reading frame triplets, except in the case of the 5 end of the coat protein gene (2.7% average difference in amino acid level, while in the case of coat protein it is 7.7%). The sequence analysis of the coat protein region of the four complete and one partial sequence indicates that the Hungarian plum pox virus strain diverges at the larger extent, similar to the El Amar strain, from which only less than half of the sequence is available.     

The complete nucleotide sequence of Pepper mottle virus-Florida RNA

Summary.  The Pepper mottle virus-Florida (PepMoV-FL) RNA genome was cloned and sequenced, and shown to consist of 9,717 nucleotides (nt) excluding the poly (A) tail. A single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3068 amino acids. Phylogenetic sequence analysis revealed that of 44 full-length viral RNA genomes analyzed within the family Potyviridae, PepMoV-FL was most closely related to PepMoV-California (PepMoV-CA), Potato virus Y-H (PVY-H), PVY-N, PVY^o and Potato virus V-DV42 (PVV-DV42). Using the PepMoV-FL sequence as a basis for comparison, the overall nucleotide sequence identity was highest between PepMoV-FL and PepMoV-CA at 93%, while the relationship was more distant with PVV-DV42 at 64% and for the PVY strains at 61%. A unique direct repeat sequence of 76 nucleotides was identified in the PepMoV-FL 3′-untranslated region (UTR), and this repeat sequence was confirmed not to occur in the PepMoV-CA sequence. Since the Florida isolate was among the first of the PepMoV isolates described, extensive biological and serological data on this isolate are available, and it has now been cloned and sequenced, we recommend that PepMoV-FL be recognized as the PepMoV type strain. Received March 25, accepted July 16, 2002     

Proteolytic activity of the plum pox potyvirus NIa-like protein in Escherichia coli

The nucleotide sequence of the small nuclear inclusion protein (NIa)-like cistron of plum pox potyvirus (PPV) has been determined. Viral proteolytic activity was expressed in Escherichia coli cells harboring plasmids with a PPV cDNA insert approximately 7000 nt long. Free PPV capsid protein was detected in these cells, but it was not produced when a mutation was introduced in the PPV cDNA insert which induced a Gln to Pro substitution at the large nuclear inclusion protein (NIb)-capsid protein junction. By mutational analysis, the NIa-like protein was determined to be responsible for the proteolytic activity. A Gln to Ser substitution at the presumed NIa-NIb junction, which inhibited proteolytic processing at the carboxyl end of the protease, had no effect on proteolytic cleavage at the NIb-capsid protein junction. In contrast with the high efficiency of proteolytic processing at the NIb-capsid protein cleavage site, processing at the ends of the PPV protease was not complete, suggesting that the PPV polyprotein, like that of other potyviruses, contains cleavage sites with different properties.     

The complete nucleotide sequence of RNA2 of blackcurrant reversion nepovirus

The complete nucleotide sequence of blackcurrant reversion nepovirus (BRV) RNA2 was determined from cDNA clones. RNA2 was 6400 nucleotides (nt) in length excluding the 3' poly(A)-tail. It contained a single open reading frame of 4878 nts encoding a polypeptide of 1626 amino acids with a calculated M(r) of 178? omitted?860. The genome organization of BRV RNA2 was similar to that of other nepoviruses, especially those with a large RNA2. The coat protein (CP) was located in the C-terminal region of the large polyprotein and contained amino acid motifs conserved among nepovirus CPs. Sequence comparisons revealed a proline (P) residue surrounded by hydrophobic amino acid residues located upstream of the CP. This P motif is conserved among the putative movement proteins of nepo-, como-, caulimo- and capilloviruses. An N-terminal domain of 350 amino acids of RNA2-encoded polyprotein shared 34 and 35% sequence identity with the N-terminal domains of tomato ringspot nepovirus RNA1- and RNA2-encoded polyproteins, respectively. Sequence identities between the N-terminal domains of BRV RNA2 and other nepoviral RNA2s were less than 20%; no common N-terminal motif was found.     

The complete nucleotide sequence of turnip mosaic virus RNA Japanese strain

Summary The complete nucleotide sequence of the RNA genome of turnip mosaic virus Japanese strain (TuMV-J) has been determined from five overlapping cDNA clones and by direct sequencing of viral RNA. The RNA sequence was 9833 nucleotides in length, excluding a 3 terminal poly(A) tail. An AUG triplet at position 130–132 was assigned as the initiation codon for the translation of the genome size viral polyprotein which would consist of 3164 amino acid residues. Interestingly, a different amino acid sequence (continuous twenty amino acids) within the cytoplasmic inclusion protein between TuMV-J and Canadian strain of TuMV was observed, caused by an insertion and a deletion of nucleotides.DDBJ/EMBL/GenBank accession number D83184.     

Replacement of the coat protein gene of plum pox potyvirus with that of zucchini yellow mosaic potyvirus: characterization of the hybrid potyvirus

Infectious hybrid virus was generated by replacing part of the coat protein gene of plum pox potyvirus with that of the zucchini yellow mosaic potyvirus. This viable hybrid contains 84.5% of zucchini yellow mosaic potyvirus coat protein gene while the rest of the sequence was derived from plum pox potyvirus. Changing the coat protein gene between these two viruses had no effect on the experimental host range. Pathogenicity, stability and replication capacity of the hybrid virus were nearly identical to the parent viruses.     

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.     

Complete nucleotide sequence of the geonomic RNA of a mild strain of Japanese yam mosaic potyvirus

Summary.  We determined the complete nucleotide sequence of a mild strain of Japanese yam mosaic potyvirus (JYMV-M) and compared it with the published sequence of severe strain of JYMV (JYMV-J1). The genomic RNA of JYMV-M is 9,760 nucleotides (nts) in length, excluding the poly (A) tail, and encodes a polyprotein of 3,132 amino acids. Among nine potential cleavage sites, only the P1 and NIa recognition sites (between 6K1 and CI) had different sequences from those of JYMV-J1. The data confirm the strain status of these two viruses with 91.1% sequence identity for the polyprotein and ∼94–97% identities for HC, CI, NIa, NIb and CP. The most divergent products P1 and P3 had 62% and 90% sequence identities respectively. Accepted September 27, 1999     

Determination of polyprotein processing sites by amino terminal sequencing of nonstructural proteins encoded by plum pox potyvirus

Nonstructural proteins of plum pox potyvirus were partially purified following a procedure described for the isolation of tobacco etch virus nuclear inclusion proteins. Plum pox virus proteins with electrophoretic mobilities corresponding to 49, 59 and 68 kDa reacted with antibodies against the 49 kDa and 54 kDa components of the nuclear inclusions and the 70 kDa component of the cylindrical inclusions of tobacco etch virus, respectively. Further purification by size exclusion high performance liquid chromatography or SDS-polyacrylamide gel electrophoresis, and amino terminal amino acid sequencing permitted the location in the plum pox virus polyprotein of the cleavage sites from which the 49 kDa (NIa-type, protease), 59 kDa (NIb-type, putative RNA replicase), and 68 kDa (CI-type) proteins originate. A 110 kDa protein which copurified with the plum pox virus inclusion proteins reacted with both anti-NIa and anti-NIb sera and had the same amino terminus as the plum pox virus 49 kDa protein, indicating that it is a non-processed 49-59 kDa polypeptide.     

Cymbidium mosaic potexvirus RNA: complete nucleotide sequence and phylogenetic analysis

Summary. The complete nucleotide sequence of the genomic RNA of cymbidium mosaic potexvirus (CymMV) was determined to be 6 227 nucleotides in length, excluding the poly (A) tail at the 3′ terminus. Similar to other potexviruses, its genome organisation is comprised of five major open reading frames (ORFs 1 to 5), encoding a M_r 160 KDa putative RNA-dependent RNA polymerase (RdRp); a M_r26KDa/13KDa/10KDa triple-gene-block (TGB) and a M_r 24 KDa coat protein. The CymMV encoded proteins shared a high degree of homology to their corresponding proteins of other members of the potexvirus group. The nucleotide sequence of the 5′ noncoding region (NCR) of CymMV and all other potexviruses initiates with GAAAA. CymMV possesses the shortest 5′ NCR among all potexviruses. Based on phylogenetic comparisons of RdRp and coat protein, CymMV shares a close relationship to PAMV, NMV, WClMV and SMYEaV. This is believed to be the first record of the complete nucleotide sequence of CymMV. Received July 24, 1996 Accepted October 2, 1996     

Cloning of the complete infectious cDNA of the plum pox virus strain PPV-Rec

Plum pox virus (PPV) is the causal agent of Sharka, considered to be the most detrimental viral disease of Prunus spp. worldwide. So far, several PPV strains have been recognized, three of them (PPV-D, PPV-M, and PPV-Rec) having shown serious economic impact in the European area. Infectious cDNA clones of plant RNA viruses are excellent tools for functional studies of viral genomes. Preparation and use of PPV-D and PPV-M infectious clones have been previously reported. Here we describe the construction of an infectious cDNA clone of the strain PPV-Rec (isolate BOR-3) by the strategy involving the subsequent exchanges of homologous BOR-3 genome parts in the backbone of the previously prepared PPV-D infectious construct. The infectivity of each intermediate chimeric cDNA as well as that of the final construct (pIC-PPV-Rec) was confirmed by biolistic transfection of Nicotiana benthamiana plants. Complete sequence of the cloned viral BOR-3 cDNA revealed 0.14% of difference at the nucleotide level compared to original BOR-3 sequence, resulting in four amino acid changes. This slight inequality was related to the population heterogeneity of the initial BOR-3 isolate; no difference in the amino acid sequence resulted from the cloning steps performed. Keywords: inter-strain chimera; biolistics; genome sequence.     

Molecular cloning and complete nucleotide sequence of galinsoga mosaic virus genomic RNA

Summary.  The complete genomic sequence of galinsoga mosaic virus (GaMV) was determined. The genome consists of 3 803 nucleotides and has five open reading frames (ORFs). The 5′ ORF (ORF 1) encodes a protein with predicted molecular mass of 23 kDa and readthrough of its amber stop codon probably yields a 82 kDa protein (ORF 2). ORFs 3 and 4 encode two polypeptides with molecular masses of 8 and 7 kDa, respectively. ORF 5 encodes the 36 kDa capsid protein. Amino acid sequence comparisons revealed that the nonstructural proteins encoded by ORFs 1, 3, and 4 were more similar to the corresponding gene products of tobacco necrosis virus, strain A, than to those of carmoviruses. Conversely, the coat protein was more similar to that of tombusviruses. The readthrough region of the viral replicase (ORF 2) had high sequence homology with that of carmo-, tombus-, and necroviruses. Computer analysis of the protein encoded by ORF 1 as well as of the corresponding product of turnip crinkle (TCV) and melon necrotic spot (MNSV) carmoviruses revealed the presence of a sequence with local hydrophobicity and hydrophobic moment characteristic of mitochondrial targeting sequence which may explain the origin of the carmovirus-induced multivesicular bodies from mitochondria. Accepted August 25, 1997 Received June 18, 1997