| characterization of the adomet-dependent guanylyltransferase activity that is associated with the n terminus of bamboo mosaic virus replicase. | bamboo mosaic virus (bamv), a member of the potexvirus group, infects primarily members of the bambusoideae. open reading frame 1 (orf1) of bamv encodes a 155-kda polypeptide that has long been postulated to be a replicase involved in the replication and formation of the cap structure at the 5' end of the viral genome. to identify and characterize the enzymatic activities associated with the n-terminal domain of the bamv orf1 protein, the intact replicase and two c-terminally truncated proteins ... | 2001 | 11134291 |
| usefulness of functional and structural solution data for the modeling of trna-like structures. | structures of large rnas are not easily solved by x-ray crystallography or by nmr spectroscopy. this paper reviews the alternate methodology based on enzymatic and chemical mapping data collected on rnas combined with graphical modeling for the construction of three-dimensional models. the different steps that lead to the establishment of the models are critically discussed. it is shown how the correctness of an rna model can be strengthened by establishing correlations between the structure and ... | 1996 | 8786997 |
| moieties in an rna promoter specifically recognized by a viral rna-dependent rna polymerase. | rnas 33 nucleotides in length can direct accurate initiation of subgenomic rna synthesis by the brome mosaic virus rna-dependent rna polymerase (rdrp), provided that the native sequences are maintained at five positions: -17, -14, -13, -11, and the +1 initiation site. the functional groups in the bases of these essential nucleotides required to interact with rdrp were examined by using chemically synthesized rnas containing base analogs at each of the five positions. analysis using a template co ... | 1998 | 9751714 |
| the cognate coat protein is required for cell-to-cell movement of a chimeric brome mosaic virus mediated by the cucumber mosaic virus movement protein. | cucumber mosaic cucumovirus (cmv) and brome mosaic bromovirus (bmv) have many similarities, including the three-dimensional structure of virions, genome organizations, and requirement of the coat protein (cp) for cell-to-cell movement. we have shown that a chimeric bmv with the cmv 3a movement protein (mp) gene instead of its own cannot move from cell to cell in chenopodium quinoa, a common permissive host for both bmv and cmv. another chimeric bmv was constructed by replacing both mp and cp gen ... | 1999 | 10600595 |
| packaging of tobacco mosaic virus subgenomic rnas by brome mosaic virus coat protein exhibits rna controlled polymorphism. | the coat protein (cp) of icosahedral brome mosaic virus (bmv) was expressed from a genetically engineered rod-shape tobacco mosaic virus. molecular characterization of the progeny recovered from symptomatic plants revealed that bmv cp selectively packaged the three subgenomic rnas of the hybrid virus into two differently sized icosahedral virus-like particles (vlps). the smaller vlps packaged only the two smaller subgenomic rnas. additional in vitro reassembly assays with bmv cp subunits and tra ... | 2000 | 10998324 |
| brome mosaic virus protein 1a recruits viral rna2 to rna replication through a 5' proximal rna2 signal. | brome mosaic virus (bmv), a positive-strand rna virus in the alphavirus-like superfamily, encodes two rna replication factors. membrane-associated 1a protein contains a helicase-like domain and rna capping functions. 2a, which is targeted to membranes by 1a, contains a central polymerase-like domain. in the absence of 2a and rna replication, 1a acts through an intergenic replication signal in bmv genomic rna3 to stabilize rna3 and induce rna3 to associate with cellular membrane. multiple results ... | 2001 | 11238847 |
| mutation of host delta9 fatty acid desaturase inhibits brome mosaic virus rna replication between template recognition and rna synthesis. | all positive-strand rna viruses assemble their rna replication complexes on intracellular membranes. brome mosaic virus (bmv) replicates its rna in endoplasmic reticulum (er)-associated complexes in plant cells and the yeast saccharomyces cerevisiae. bmv encodes rna replication factors 1a, with domains implicated in rna capping and helicase functions, and 2a, with a central polymerase-like domain. factor 1a interacts independently with the er membrane, viral rna templates, and factor 2a to form ... | 2001 | 11160714 |
| enhancer-like activity of a brome mosaic virus rna promoter. | as with transcription from dna templates, rna synthesis from viral rna templates must initiate accurately. rna sequences named specificity and initiation determinants allow recognition of and coordinated interaction with the viral replication enzyme. using enriched replicase from brome mosaic virus (bmv)-infected plants and variants of the promoter template for minus-strand and subgenomic rna initiation, we found that a specificity determinant for minus-strand initiation could function at variab ... | 2003 | 12525617 |
| complete nucleotide sequence of spring beauty latent virus, a bromovirus infectious to arabidopsis thaliana. | spring beauty latent virus (sblv), a bromovirus, systemically and efficiently infected arabidopsis thaliana, whereas the well-studied bromoviruses brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) did not infect and poorly infected a. thaliana, respectively. we constructed biologically active cdna clones of sblv genomic rnas and determined their complete nucleotide sequences. interestingly, sblv rna3 contains both the box b motif in the intercistronic region, as does bmv, and the ... | 2003 | 12536302 |
| determination of the complete amino acid sequence for the coat protein of brome mosaic virus by time-of-flight mass spectrometry. evidence for mutations associated with change of propagation host. | time-of-flight mass spectrometry (tofms) has been applied to determine the complete coat protein amino acid sequences of a number of distinct brome mosaic virus (bmv) isolates. ionization was carried out by both electrospray ionization and matrix-assisted laser desorption/ionization (maldi). after determining overall coat protein masses, the proteins were digested with trypsin or lys-c proteinases, and the digestion products were analyzed in a maldi qqtof mass spectrometer. the n terminus of the ... | 2001 | 11274180 |
| efficient and specific initiation of subgenomic rna synthesis by cucumber mosaic virus replicase in vitro requires an upstream rna stem-loop. | we defined the minimal core promoter sequences responsible for efficient and accurate initiation of cucumber mosaic virus (cmv) subgenomic rna4. the necessary sequence maps to positions -28 to +15 relative to the initiation cytidylate used to initiate rna synthesis in vivo. positions -28 to -5 contain a 9-bp stem and a 6-nucleotide purine-rich loop. considerable changes in the stem and the loop are tolerated for rna synthesis, including replacement with a different stem-loop. in a template compe ... | 2000 | 11070017 |
| detecting structural changes in viral capsids by hydrogen exchange and mass spectrometry. | amide hydrogen exchange and mass spectrometry have been used to study the ph-induced structural changes in the capsid of brome mosaic virus (bmv). capsid protein was labeled in a structurally sensitive way by incubating intact viral particles in d(2)o at ph 5.4 and 7.3. deuterium levels in the intact coat protein and its proteolytic fragments were determined by mass spectrometry. the largest deuterium increases induced by structural alteration occurred in the regions around the quasi-threefold a ... | 2001 | 11369862 |
| specific tyrosylation of the bulky trna-like structure of brome mosaic virus rna relies solely on identity nucleotides present in its amino acid-accepting domain. | residues specifying aminoacylation by yeast tyrosyl-trna synthetase (tyrrs) of the trna-like structure present at the 3'-end of brome mosaic virus (bmv) rna were determined by the in vitro approach using phage t7 transcripts. they correspond to nucleotides equivalent to base-pair c1-g72 and discriminator base a73 in the amino acid-acceptor branch of the molecule. no functional equivalents of the tyrosine anticodon residues, shown to be weakly involved in tyrosine identity of canonical trna(tyr), ... | 2001 | 11371160 |
| conversion in the requirement of coat protein in cell-to-cell movement mediated by the cucumber mosaic virus movement protein. | plant viruses have movement protein (mp) gene(s) essential for cell-to-cell movement in hosts. cucumber mosaic virus (cmv) requires its own coat protein (cp) in addition to the mp for intercellular movement. our present results using variants of both cmv and a chimeric brome mosaic virus with the cmv mp gene revealed that cmv mp truncated in its c-terminal 33 amino acids has the ability to mediate viral movement independently of cp. coexpression of the intact and truncated cmv mps extremely redu ... | 2001 | 11483749 |
| rnai and viral vectors as useful tools in the functional genomics of plants. construction of bmv-based vectors for rna delivery into plant cells. | the sequencing of several complete genomes and the development of a dna microarray technology are among the most important achievements of molecular biology. they gave the proper grounds for the development of modern functional genomics. however, there is one additional condition which needs to be satisfied to truely enable the study of how a genome works: a suitable method of selectively inducing and silencing the expression of each individual gene. the methods used so far have usually only per ... | 2002 | 12378257 |
| crystallization of brome mosaic virus and t = 1 brome mosaic virus particles following a structural transition. | brome mosaic virus (bmv), a t = 3 icosahedral plant virus, can be dissociated into coat protein subunits and subunit oligomers at ph 7.5 in the presence of concentrated salts. we have found that during the course of this treatment the coat protein subunits are cleaved, presumably by plant cell proteases still present in the preparation, between amino acids 35 and 36. the truncated protein subunits will then reorganize into t = 1 icosahedral particles and can be crystallized from sodium malonate. ... | 2001 | 11485397 |
| inducible high-level mrna amplification system by viral replicase in transgenic plants. | we have constructed a new system for inducible high-level expression of mrna for foreign genes in transgenic plants by introducing a glucocorticoid-inducible transcription system into the previously developed "mrna amplification system" where target mrna can be amplified as a subgenomic rna by the replicase of a plant tripartite rna virus, brome mosaic virus (bmv). in the new amplification system, the amplification of mrna is tightly regulated by the expression of a subunit of the bmv replicase. ... | 2001 | 11489185 |
| studies on functional interaction between brome mosaic virus replicase proteins during rna recombination, using combined mutants in vivo and in vitro. | two viral proteins, 1a and 2a, direct replication of brome mosaic bromovirus (bmv) rnas as well as they participate in bmv rna recombination. to study the relationship between replication and recombination, double bmv variants that carried mutations in 1a and 2a genes were tested. the observed effects revealed that the 1a helicase and 2a n-terminal or core domains were functionally linked during both processes in vivo. the use of a series of mutant bmv replicase (rdrp) preparations demonstrated ... | 2001 | 11601925 |
| brome mosaic virus replicase proteins localize with the movement protein at infection-specific cytoplasmic inclusions in infected barley leaf cells. | subcellular localization of the brome mosaic virus replicase-related 1a and 2a proteins, and the 3a movement protein in infected barley leaves was examined by immunogold electron microscopy. the 1a and 2a proteins colocalized at infection-specific electron-dense cytoplasmic inclusions. the 3a protein was also detected in these inclusions. the inclusions were oval or amorphous, and contained electron-lucent regions. electron microscopic autoradiography showed that the inclusions were sites of [3h ... | 2001 | 11676421 |
| a mutant viral rna promoter with an altered conformation retains efficient recognition by a viral rna replicase through a solution-exposed adenine. | brome mosaic virus (bmv) genomic minus-strand rna synthesis requires an rna motif named stem-loop c (slc). an nmr-derived solution structure of slc was reported by kim et al. (nature struc biol, 2000, 7:415-423) to contain three replicase-recognition elements, the most important of which is a stable stem with a terminal trinucleotide loop, 5'aua3'. the 5'-most adenine of the triloop is rigidly fixed to the stem helix by interactions that require the 3'-most adenine, which is called a clamped ade ... | 2001 | 11680852 |
| functions of the 3'-untranslated regions of positive strand rna viral genomes. | positive strand rna viral genomes are unique in the viral world in serving a dual role as mrna and replicon. since the origin of the minus-strand rna replication intermediate is at the 3'-end of the genome, the 3'-untranslated region (utr) clearly plays a role in viral rna replication. the messenger role of this same rna likely places functional demands on the 3'-utr to serve roles typical of cellular mrnas, including the regulation of rna stability and translation. current understanding indicat ... | 1999 | 11701820 |
| identification of sequences in brome mosaic virus replicase protein 1a that mediate association with endoplasmic reticulum membranes. | rna replication of all positive-strand rna viruses is closely associated with intracellular membranes. brome mosaic virus (bmv) rna replication occurs on the perinuclear region of the endoplasmic reticulum (er), both in its natural plant host and in the yeast saccharomyces cerevisiae. the only viral component in the bmv rna replication complex that localizes independently to the er is 1a, a multifunctional protein with an n-terminal rna capping domain and a c-terminal helicase-like domain. the o ... | 2001 | 11711627 |
| cis-acting elements required for efficient packaging of brome mosaic virus rna3 in barley protoplasts. | brome mosaic virus (bmv) is a positive-sense rna plant virus, the tripartite genomic rnas of which are separately packaged into virions. rna3 is copackaged with subgenomic rna4. in barley protoplasts coinoculated with rna1 and rna2, an rna3 mutant with a 69-nucleotide (nt) deletion in the 3'-proximal region of the 3a open reading frame (orf) was very poorly packaged compared with other rna3 mutants and wild-type rna3, despite their comparable accumulation in the absence of coat protein. computer ... | 2003 | 12941908 |
| spherical plant viruses: interactions in solution, phase diagrams and crystallization of brome mosaic virus. | brome mosaic virus (bmv) is a small icosahedral plant virus of mean diameter 268 a. interactions between bmv particles in solution were studied by means of small-angle x-ray scattering in order to find crystallization conditions. the interactions between biomacromolecules as large as these viruses have not yet been systematically studied by this method. as it is known that usually proteins crystallize in, or close to, attractive regimes, the interactions between bmv particles in solution were st ... | 2001 | 11717492 |
| stabilization of brome mosaic virus by magnesium and calcium. | | 1963 | 14014903 |
| rna recombination in brome mosaic virus: effects of strand-specific stem-loop inserts. | a model system of a single-stranded trisegment brome mosaic bromovirus (bmv) was used to analyze the mechanism of homologous rna recombination. elements capable of forming strand-specific stem-loop structures were inserted at the modified 3' noncoding regions of bmv rna3 and rna2 in either positive or negative orientations, and various combinations of parental rnas were tested for patterns of the accumulating recombinant rna3 components. the structured negative-strand stem-loops that were insert ... | 2002 | 12438591 |
| trna elements mediate the assembly of an icosahedral rna virus. | trnas, the adapter molecules in protein synthesis, also serve as metabolic cofactors and as primers for viral rna-directed dna synthesis. the genomic and subgenomic rnas of some plant viruses have a 3'-terminal trna-like structure (tls) that can accept a specific amino acid and serve as a site for initiation of replication and as a simple telomere. we report a previously undescribed role for the tls of brome mosaic virus (bmv), and potentially for cellular trna, in mediating the assembly of its ... | 2002 | 11782536 |
| foreign complementary sequences facilitate genetic rna recombination in brome mosaic virus. | we have demonstrated that local antisense sequences can mediate genetic recombination within the 3' noncoding region among brome mosaic virus (bmv) rnas (p. nagy and j. j. bujarski, 1993, proc. natl. acad. sci. usa 90, 6390-6394). here we show that foreign complementary inserts can direct crossovers between bmv rna3 components within an internal region. a 170-nt polynucleotide derived from the cowpea chlorotic mottle virus (ccmv) rna3 was inserted just upstream of the initiation codon of the bmv ... | 1995 | 11831722 |
| efficient translation of alfamovirus rnas requires the binding of coat protein dimers to the 3' termini of the viral rnas. | the coat protein (cp) of alfalfa mosaic virus (amv) is required to initiate infection by the viral tripartite rna genome whereas infection by the tripartite brome mosaic virus (bmv) genome is independent of cp. amv cp stimulates translation of amv rna in vivo 50- to 100-fold. the 3' untranslated region (utr) of the amv subgenomic cp messenger rna 4 contains at least two cp binding sites. a cp binding site in the 3'-terminal 112 nucleotides of rna 4 was found to be required for efficient translat ... | 2004 | 14718638 |
| the brome mosaic virus subgenomic promoter hairpin is structurally similar to the iron-responsive element and functionally equivalent to the minus-strand core promoter stem-loop c. | in the bromoviridae family of plant viruses, trinucleotide hairpin loops play an important role in rna transcription. recently, we reported that brome mosaic virus (bmv) subgenomic (sg) transcription depended on the formation of an unusual triloop hairpin. by native gel electrophoresis, enzymatic structure probing, and nmr spectroscopy it is shown here that in the absence of viral replicase the hexanucleotide loop 5'c1auag5a3' of this rna structure can adopt a pseudo trinucleotide loop conformat ... | 2002 | 11873757 |
| positional effect of deletions on viability, especially on encapsidation, of brome mosaic virus d-rna in barley protoplasts. | brome mosaic virus (bmv), a tripartite rna plant virus, accumulates rna3-derived defective rnas (d-rnas) in which 477-500 nucleotides (nt) are deleted in the central region of the 3a protein open reading frame (orf), after prolonged infection in barley. in the present study, six artificial d-rnas (ad-rnas), having deletions of the same size as the naturally occurring d-rna but at different positions in the 3a orf, were constructed and tested for their amplification and encapsidation in barley pr ... | 2002 | 11886251 |
| the crystallographic structure of brome mosaic virus. | the structure of brome mosaic virus (bmv), the type member of the bromoviridae family, has been determined from a single rhombohedral crystal by x-ray diffraction, and refined to an r value of 0.237 for data in the range 3.4-40.0 a. the structure, which represents the native, compact form at ph 5.2 in the presence of 0.1 m mg(2+), was solved by molecular replacement using the model of cowpea chlorotic mottle virus (ccmv), which bmv closely resembles. the bmv model contains amino acid residues 41 ... | 2002 | 11916381 |
| stop codon decoding in candida albicans: from non-standard back to standard. | the human pathogen candida albicans translates the standard leucine-cug codon as serine. this genetic code change is mediated by a novel ser-trna(cag), which induces aberrant mrna decoding in vitro, resulting in retardation of the electrophoretic mobility of the polypeptides synthesized in its presence. these non-standard decoding events have been attributed to readthrough of the uag and uga stop codons encoded by the brome mosaic virus rna 4, which codes for the virion coat protein, and the rab ... | 2002 | 12112228 |
| the molecular variability analysis of the rna 3 of fifteen isolates of prunus necrotic ringspot virus sheds light on the minimal requirements for the synthesis of its subgenomic rna. | the nucleotide sequences of the rna 3 of fifteen isolates of prunus necrotic ringspot virus (pnrsv) varying in the symptomatology they cause in six different prunus spp. were determined. analysis of the molecular variability has allowed, in addition to study the phylogenetic relationships among them, to evaluate the minimal requirements for the synthesis of the subgenomic rna in ilarvirus genus and their comparison to other members of the bromoviridae family. computer assisted comparisons led re ... | 2002 | 12206311 |
| time-resolved scattering investigations of brome mosaic virus microcrystals appearance. | the behavior of brome mosaic virus in solution as a function of physico-chemical conditions has already been characterized by small angle x-ray scattering studies. the most striking result was that the precipitates induced by the addition of polyethylene glycol were in fact made of microcrystals. this result was reinvestigated on the id2 beamline at esrf (grenoble, france) to determine whether there was an amorphous state before the organized one, and measure the necessary period of latency for ... | 2002 | 12351863 |
| mutation of host dnaj homolog inhibits brome mosaic virus negative-strand rna synthesis. | the replication of positive-strand rna viruses involves not only viral proteins but also multiple cellular proteins and intracellular membranes. in both plant cells and the yeast saccharomyces cerevisiae, brome mosaic virus (bmv), a member of the alphavirus-like superfamily, replicates its rna in endoplasmic reticulum (er)-associated complexes containing viral 1a and 2a proteins. prior to negative-strand rna synthesis, 1a localizes to er membranes and recruits both positive-strand bmv rna templa ... | 2003 | 12584324 |
| the c terminus of the movement protein of brome mosaic virus controls the requirement for coat protein in cell-to-cell movement and plays a role in long-distance movement. | the 3a movement protein (mp) plays a central role in the movement of brome mosaic virus (bmv). to identify the functional regions in bmv mp, 24 alanine-scanning (as) mp mutants of bmv were constructed. infectivity of the as mutants in the host plant chenopodium quinoa showed that the central region of bmv mp is important for viral movement and both termini of bmv mp have effects on the development of systemic symptoms. a green-fluorescent-protein-expressing rna3-based bmv vector containing a 2a ... | 2004 | 15166461 |
| dissecting the requirement for subgenomic promoter sequences by rna recombination of brome mosaic virus in vivo: evidence for functional separation of transcription and recombination. | previously, we and others mapped an increased homologous recombination activity within the subgenomic promoter (sgp) region in brome mosaic virus (bmv) rna3. in order to correlate sgp-mediated recombination and transcription, in the present work we used bmv rna3 constructs that carried altered sgp repeats. we observed that the removal or extension of the poly(u) tract reduced or increased recombination, respectively. deletion of the sgp core hairpin or its replacement by a different stem-loop st ... | 2004 | 15280464 |
| brome mosaic virus rna replication: revealing the role of the host in rna virus replication. | the replication of positive-strand rna viruses is a complex multi-step process involving interactions between the viral genome, virus-encoded replication factors, and host factors. the plant virus brome mosaic virus (bmv) has served as a model for positive-strand rna virus replication, recombination, and virion assembly. this review addresses recent findings on the identification and characterization of host factors in bmv rna replication. to date, all characterized host factors facilitate steps ... | 2003 | 12651962 |
| the movement protein gene is involved in the virus-specific requirement of the coat protein in cell-to-cell movement of bromoviruses. | brome mosaic virus (bmv) requires the coat protein (cp) for cell-to-cell movement whereas cowpea chlorotic mottle virus (ccmv), from the same genus, does not. chimeric viruses created by exchanging the movement protein (mp) gene between the viruses can move from cell to cell. we show that interference in cp expression impaired the movement of the chimeric ccmv with the bmv mp gene but not of the chimeric bmv with the ccmv mp gene. we thus conclude that the mp gene plays a crucial role in determi ... | 2003 | 12664302 |
| depurination of ribosomal rna and inhibition of viral rna translation by an antiviral protein of celosia cristata. | an antiviral protein (25 kd) isolated from leaves of celosia cristata (ccp 25) was tested for depurination study on ribosomal rna from yeast. ribosomal rna yielded 360 nucleotide base fragment after treatment with ccp 25 indicating that ccp 25 was a ribosome inactivating protein. ccp 25 also inhibited translation of brome mosaic virus (bmv) and pokeweed mosaic virus (pmv) rnas in rabbit reticulocyte translation system. the radioactive assay showed that incorporation of [35s]-methionine was less ... | 2002 | 12693705 |
| stable rna structures can repress rna synthesis in vitro by the brome mosaic virus replicase. | a 15-nucleotide (nt) unstructured rna with an initiation site but lacking a promoter could direct the initiation of rna synthesis by the brome mosaic virus (bmv) replicase in vitro. however, bmv rna with a functional initiation site but a mutated promoter could not initiate rna synthesis either in vitro or in vivo. to explain these two observations, we hypothesize that rna structures that cannot function as promoters could prevent rna synthesis by the bmv rna replicase. we documented that four d ... | 2003 | 12702814 |
| brome mosaic virus rna syntheses in vitro and in barley protoplasts. | the rna replicase extracted from brome mosaic virus (bmv)-infected plants has been used to characterize the cis-acting elements for rna synthesis and the mechanism of rna synthesis. minus-strand rna synthesis in vitro requires a structure named stem-loop c (slc) that contains a clamped adenine motif. in vitro, there are several specific requirements for slc recognition. we examined whether these requirements also apply to bmv replication in barley protoplasts. bmv rna3s with mutations in slc wer ... | 2003 | 12719563 |
| characterization of a novel barley protein, hcp1, that interacts with the brome mosaic virus coat protein. | brome mosaic virus (bmv) requires the coat protein (cp) not only for encapsidation but also for viral cell-to-cell and long-distance movement in barley plants. this suggests that bmv infection is controlled by interactions of cp with putative host factors as well as with viral components. to identify the host factors that interact with bmv cp, we screened a barley cdna library containing 2.4 x 10(6) independent clones, using a yeast two-hybrid system. using full-length and truncated bmv cps as b ... | 2003 | 12744464 |
| a transcriptionally active subgenomic promoter supports homologous crossovers in a plus-strand rna virus. | genetic rna recombination plays an important role in viral evolution, but its molecular mechanism is not well understood. in this work we describe homologous rna recombination activity that is supported by a subgenomic promoter (sgp) region in the rna3 segment of brome mosaic bromovirus (bmv), a tripartite plus-strand rna virus. the crossover frequencies were determined by coinoculations with pairs of bmv rna3 variants that carried a duplicated sgp region flanked by marker restriction sites. a r ... | 2003 | 12767997 |
| use of spring beauty latent virus to identify compatible interactions between bromovirus components required for virus infection. | spring beauty latent virus (sblv) is a member of the genus bromovirus, and is closely related to brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv). compatible interactions between viral components are required for successful infection of plants by bmv and ccmv. to further our understanding of interactions between bromovirus components, we used sblv to produce reassortants among the three bromoviruses. we found that sblv rna 2 functioned with heterologous bromovirus rna 1 in infec ... | 2003 | 12771403 |
| crystallographic structure of the t=1 particle of brome mosaic virus. | t=1 icosahedral particles of amino terminally truncated brome mosaic virus (bmv) protein were created by treatment of the wild-type t=3 virus with 1m cacl2 and crystallized from sodium malonate. diffraction data were collected from frozen crystals to beyond 2.9 a resolution and the structure determined by molecular replacement and phase extension. the particles are composed of pentameric capsomeres from the wild-type virions which have reoriented with respect to the original particle pentameric ... | 2005 | 15713465 |
| yeast lsm1p-7p/pat1p deadenylation-dependent mrna-decapping factors are required for brome mosaic virus genomic rna translation. | previously, we used the ability of the higher eukaryotic positive-strand rna virus brome mosaic virus (bmv) to replicate in yeast to show that the yeast lsm1 gene is required for recruiting bmv rna from translation to replication. here we extend this observation to show that lsm1p and other components of the lsm1p-lsm7p/pat1p deadenylation-dependent mrna decapping complex were also required for translating bmv rnas. inhibition of bmv rna translation was selective, with no effect on general cellu ... | 2003 | 12773554 |
| gold nanoparticles as spectroscopic enhancers for in vitro studies on single viruses. | gold particles with diameters between 2.5 and 4.5 nm have been introduced in the inner cavity of an icosahedral brome mosaic virus. the optical properties of single gold-marked virions have been tested in-vitro with respect to the characteristic plasmon polariton resonance. the shift in the plasmon polariton resonance of a single au particle encapsulated in a virus with respect to a free particle in solution indicates a close interaction between the basic residues on the inner wall of the capsid ... | 2003 | 12785770 |
| rna-dependent rna polymerase complex of brome mosaic virus: analysis of the molecular structure with monoclonal antibodies. | viral rna-dependent rna polymerase (rdrp) plays crucial roles in the genomic replication and subgenomic transcription of brome mosaic virus (bmv), a positive-stranded rna plant virus. bmv rdrp is a complex of virus-encoded 1a and 2a proteins and some cellular factors, and associates with the endoplasmic reticulum at an infection-specific structure in the cytoplasm of host cells. in this study, we investigate the gross structure of the active bmv rdrp complex using monoclonal antibodies raised ag ... | 2002 | 12388824 |
| packaging of brome mosaic virus rna3 is mediated through a bipartite signal. | the three genomic and a single subgenomic rna of brome mosaic virus (bmv), an rna virus infecting plants, are packaged by a single-coat protein (cp) into three morphologically indistinguishable icosahedral virions with t = 3 quasi-symmetry. genomic rnas 1 and 2 are packaged individually into separate particles whereas genomic rna3 and subgenomic rna4 (coat protein mrna) are copackaged into a single particle. we report here that packaging of dicistronic rna3 requires a bipartite signal. a highly ... | 2003 | 12941883 |
| properties of brome mosaic virus and its related antigens. | | 1961 | 13904117 |
| homologous crossovers among molecules of brome mosaic bromovirus rna1 or rna2 segments in vivo. | previously we demonstrated frequent homologous crossovers among molecules of the rna3 segment in the tripartite brome mosaic bromovirus (bmv) rna genome (a. bruyere, m. wantroba, s. flasinski, a. dzianott, and j. j. bujarski, j. virol. 74:4214-4219, 2000). to further our knowledge about mechanisms of viral rna genome variability, in this paper we have studied homologous recombination in bmv rna1 and rna2 components during infection. we have found that basal rna-rna crossovers could occur within ... | 2005 | 15827188 |
| cucumovirus- and bromovirus-encoded movement functions potentiate cell-to-cell movement of tobamo- and potexviruses. | cucumber mosaic virus (cmv, a cucumovirus) and brome mosaic virus (bmv, a bromovirus) require the coat protein (cp) in addition to the 3a movement protein (mp) for cell-to-cell movement, while cowpea chlorotic mottle virus (ccmv, a bromovirus) does not. using bombardment-mediated transcomplementation assays, we investigated whether the movement functions encoded by these viruses potentiate cell-to-cell movement of movement-defective tomato mosaic virus (tomv, a tobamovirus) and potato virus x (p ... | 2003 | 14592759 |
| membrane synthesis, specific lipid requirements, and localized lipid composition changes associated with a positive-strand rna virus rna replication protein. | multifunctional rna replication protein 1a of brome mosaic virus (bmv), a positive-strand rna virus, localizes to the cytoplasmic face of endoplasmic reticulum (er) membranes and induces er lumenal spherules in which viral rna synthesis occurs. we previously showed that bmv rna replication in yeast is severely inhibited prior to negative-strand rna synthesis by a single-amino-acid substitution in the ole1w allele of yeast delta9 fatty acid (fa) desaturase, which converts saturated fas (sfas) to ... | 2003 | 14610203 |
| systematic, genome-wide identification of host genes affecting replication of a positive-strand rna virus. | positive-strand rna viruses are the largest virus class and include many pathogens such as hepatitis c virus and the severe acute respiratory syndrome coronavirus (sars). brome mosaic virus (bmv) is a representative positive-strand rna virus whose rna replication, gene expression, and encapsidation have been reproduced in the yeast saccharomyces cerevisiae. by using traditional yeast genetics, host genes have been identified that function in controlling bmv translation, selecting bmv rnas as rep ... | 2003 | 14671320 |
| template sequence near the initiation nucleotide can modulate brome mosaic virus rna accumulation in plant protoplasts. | bromoviral templates for plus-strand rna synthesis are rich in a or u nucleotides in comparison to templates for minus-strand rna synthesis. previous studies demonstrated that plus-strand rna synthesis by the brome mosaic virus (bmv) rna replicase is more efficient if the template contains an a/u-rich template sequence near the initiation site (k. sivakumaran and c. c. kao, j. virol. 73:6415-6423, 1999). these observations led us to examine the effects of nucleotide changes near the template's i ... | 2004 | 14722272 |
| an alternate pathway for recruiting template rna to the brome mosaic virus rna replication complex. | the multidomain rna replication protein 1a of brome mosaic virus (bmv), a positive-strand rna virus in the alphavirus-like superfamily, plays key roles in assembly and function of the viral rna replication complex. 1a, which encodes rna capping and helicase-like domains, localizes to endoplasmic reticulum membranes, recruits bmv 2a polymerase and viral rna templates, and forms membrane-bound, capsid-like spherules in which rna replication occurs. cis-acting signals necessary and sufficient for r ... | 2003 | 12551995 |
| the au-rich rna recombination hot spot sequence of brome mosaic virus is functional in tombusviruses: implications for the mechanism of rna recombination. | rna recombination can be facilitated by recombination signals present in viral rnas. among such signals are short sequences with high au contents that constitute recombination hot spots in brome mosaic virus (bmv) and retroviruses. in this paper, we demonstrate that a defective interfering (di) rna, a model template associated with tomato bushy stunt virus (tbsv), a tombusvirus, undergoes frequent recombination in plants and protoplast cells when it carries the au-rich hot spot sequence from bmv ... | 2004 | 14963125 |
| infection and rna recombination of brome mosaic virus in arabidopsis thaliana. | ecotypes of arabidopsis thaliana supported the replication and systemic spread of brome mosaic virus (bmv) rnas. infection was induced either by manual inoculation with viral rna or by bmv virions, demonstrating that virus disassembly did not prevent infection. when in vitro-transcribed bmv rnas 1-3 were used, production of subgenomic rna4 was observed, showing that bmv rna replication and transcription had occurred. furthermore, inoculations of the transgenic arabidopsis line that expressed a s ... | 2004 | 14972517 |
| cell-to-cell movement of alfalfa mosaic virus can be mediated by the movement proteins of ilar-, bromo-, cucumo-, tobamo- and comoviruses and does not require virion formation. | rna 3 of alfalfa mosaic virus (amv) encodes the movement protein (mp) and coat protein (cp). chimeric rna 3 with the amv mp gene replaced by the corresponding mp gene of prunus necrotic ringspot virus, brome mosaic virus, cucumber mosaic virus or cowpea mosaic virus efficiently moved from cell-to-cell only when the expressed mp was extended at its c-terminus with the c-terminal 44 amino acids of amv mp. mp of tobacco mosaic virus supported the movement of the chimeric rna 3 whether or not the mp ... | 2006 | 16316673 |
| effects of artificial codon changes in the movement protein gene on adaptation of a hybrid bromovirus to cowpea. | a hybrid cowpea chlorotic mottle virus(ccmv) with the movement protein (mp) gene replaced with that of the closely related brome mosaic virus cannot infect cowpea systemically. twenty-nine spontaneous mutants from the hybrid ccmv capable of systemic infection in cowpea appeared through biased codon changes that resulted in lys or arg at five specific positions in the mp gene. in this study, we report that systemic infection of cowpea with the hybrid ccmv can be achieved by artificial codon chang ... | 2004 | 14978339 |
| alternate, virus-induced membrane rearrangements support positive-strand rna virus genome replication. | all positive-strand rna [(+)rna] viruses replicate their rna on intracellular membranes, often in association with spherular invaginations of the target membrane. for brome mosaic virus, we previously showed that such spherules serve as compartments or mini-organelles for rna replication and that their assembly, structure, and function have similarities to the replicative cores of retrovirus and double-stranded rna virus virions. some other (+)rna viruses conduct rna replication in association w ... | 2004 | 15280537 |
| subgenomic rna as a riboregulator: negative regulation of rna replication by barley yellow dwarf virus subgenomic rna 2. | barley yellow dwarf virus (bydv) generates three 3'-coterminal subgenomic rnas (sgrnas) in infected cells. translation of bydv genomic rna (grna) and sgrna1 is mediated by the bydv cap-independent translation element (bte) in the 3' untranslated region. sgrnas 2 and 3 are unlikely to be mrnas. we proposed that accumulation of sgrna2, which contains the bte in its 5' utr, regulates bydv replication by trans-inhibiting translation of the viral polymerase from genomic rna (grna). here, we tested th ... | 2004 | 15351207 |
| birth and growth kinetics of brome mosaic virus microcrystals. | the early steps of crystal nucleation and growth in brome mosaïc virus and polyethylene glycol mixtures were analyzed using time-resolved x-ray scattering (at the european synchrotron radiation facility, grenoble, france). the system was chosen as a crystallization model since the phase diagram of the macromolecule/polymer mixture was known to present, at high polymer concentration, a solid, precipitated phase made of the synchronized formation of a large number of microcrystals. the precipitati ... | 2004 | 15454465 |
| [monitoring of cereal viruses in agrocenoses of ukraine]. | different ukrainian agrocenoses have been investigated for the presence of the most harmful cereals viruses. the highest percent of virus infected plants was established in the kyiv, chernigiv, vynytsya and kherson regions. bromegrass mosaic bromovirus (bmv), barley yellow dwarf luteovirus (bydv-pav), wheat streak mosaic rymovirus (wsmv) are the most distributed viruses. the soil transmitted viruses such as wheat spindle streak mosaic bymovirus (wssmv), barley mild mosaic bymovirus (bammv), soil ... | 2005 | 16493890 |
| replicase-binding sites on plus- and minus-strand brome mosaic virus rnas and their roles in rna replication in plant cells. | the cis-acting elements for brome mosaic virus (bmv) rna synthesis have been characterized primarily for rna3. to identify additional replicase-binding elements, nested fragments of all three of the bmv rnas, both plus- and minus-sense fragments, were constructed and tested for binding enriched bmv replicase in a template competition assay. ten rna fragments containing replicase-binding sites were identified; eight were characterized further because they were more effective competitors. all eigh ... | 2004 | 15564452 |
| modeling the helicase domain of brome mosaic virus 1a replicase. | brome mosaic virus (bmv) is a representative member of positive-strand rna viruses. the 1a replicase from bmv is a membrane protein of unknown structure with a methyltransferase n-terminal domain and a putative helicase activity in the c-terminal domain. in order to make a functional prediction of the helicase activity of the bmv 1a c-terminal domain, we have built a model of its structure. the use of fold recognition servers hinted at two different superfamilies of helicases [superfamily 1 (sf1 ... | 2004 | 15597207 |
| repair of the trna-like cca sequence in a multipartite positive-strand rna virus. | the 3' portions of plus-strand brome mosaic virus (bmv) rnas mimic cellular trnas. nucleotide substitutions or deletions in the 3'cca of the trna-like sequence (tls) affect minus-strand initiation unless repaired. we observed that 2-nucleotide deletions involving the cca 3' sequence in one or all bmv rnas still allowed rna accumulation in barley protoplasts at significant levels. alterations of cca to gga in only bmv rna3 also allowed rna accumulation at wild-type levels. however, substitutions ... | 2005 | 15650168 |
| mutual interference between genomic rna replication and subgenomic mrna transcription in brome mosaic virus. | replication by many positive-strand rna viruses includes genomic rna amplification and subgenomic mrna (sgrna) transcription. for brome mosaic virus (bmv), both processes occur in virus-induced, membrane-associated compartments, require bmv replication factors 1a and 2a, and use negative-strand rna3 as a template for genomic rna3 and sgrna syntheses. to begin elucidating their relations, we examined the interaction of rna3 replication and sgrna transcription in saccharomyces cerevisiae expressin ... | 2005 | 15650170 |
| dispensability of 3' trna-like sequence for packaging cowpea chlorotic mottle virus genomic rnas. | the 3' ends of three genomic rnas (grnas) of cowpea chlorotic mottle virus (ccmv) terminate in a highly conserved trna-like structure (3'tls). to examine the intrinsic role played the 3'tls in packaging, the competence of each grna lacking the 3' tls (deltatls-grna) to interact with dissociated coat protein (cp) subunits and form virions was assayed in vitro. in contrast to the well established requirement for the participation of either viral 3'tls or host-trnas in the assembly of rna-containin ... | 2005 | 15680430 |
| atomic force microscopy analysis of icosahedral virus rna. | single-stranded genomic rnas from four icosahedral viruses (poliovirus, turnip yellow mosaic virus (tymv), brome mosaic virus (bmv), and satellite tobacco mosaic virus (stmv)) along with the rna from the helical tobacco mosaic virus (tmv) were extracted using phenol/chloroform. the rnas were imaged using atomic force microscopy (afm) under dynamic conditions in which the rna was observed to unfold. rnas from the four icosahedral viruses initially exhibited highly condensed, uniform spherical sha ... | 2005 | 15733916 |
| modular rna architecture revealed by computational analysis of existing pseudoknots and ribosomal rnas. | modular architecture is a hallmark of rna structures, implying structural, and possibly functional, similarity among existing rnas. to systematically delineate the existence of smaller topologies within larger structures, we develop and apply an efficient rna secondary structure comparison algorithm using a newly developed two-dimensional rna graphical representation. our survey of similarity among 14 pseudoknots and subtopologies within ribosomal rnas (rrnas) uncovers eight pairs of structurall ... | 2005 | 15745998 |
| characterization of a novel 5' subgenomic rna3a derived from rna3 of brome mosaic bromovirus. | the synthesis of 3' subgenomic rna4 (sgrna4) by initiation from an internal sg promoter in the rna3 segment was first described for brome mosaic bromovirus (bmv), a model tripartite positive-sense rna virus (w. a. miller, t. w. dreher, and t. c. hall, nature 313:68-70, 1985). in this work, we describe a novel 5' sgrna of bmv (sgrna3a) that we propose arises by premature internal termination and that encapsidates in bmv virions. cloning and sequencing revealed that, unlike any other bmv rna segme ... | 2006 | 17005659 |
| pokeweed antiviral protein inhibits brome mosaic virus replication in plant cells. | pokeweed antiviral protein (pap) is a ribosome-inactivating protein isolated from the pokeweed plant (phytolacca americana) that inhibits the proliferation of several plant and animal viruses. we have shown previously that pap and nontoxic mutants of pap can directly depurinate brome mosaic virus (bmv) rna in vitro, resulting in reduced viral protein translation. here we expand on these initial studies and, using a barley protoplast system, demonstrate that recombinant pap and nontoxic mutants i ... | 2005 | 15764597 |
| synthesis of infectious in vitro transcripts from cassia yellow blotch bromovirus cdna clones and a reassortment analysis with other bromoviruses in protoplasts. | cassia yellow blotch virus (cybv), genus bromovirus, was isolated from the australian native legume, cassia pleurocarpa, in western queensland, and its host range was found to be distinct from other bromoviruses. in this study, cybv was shown to infect systemically and efficiently a model plant species, arabidopsis thaliana, as we recently reported for another bromovirus, spring beauty latent virus (sblv). we constructed full-length cdna clones of cybv genomic rnas from which infectious in vitro ... | 2005 | 15770356 |
| natural isolates of brome mosaic virus with the ability to move from cell to cell independently of coat protein. | brome mosaic virus (bmv) requires encapsidation-competent coat protein (cp) for cell-to-cell movement and the 3a movement protein (mp) is involved in determining the cp requirement for bmv movement. however, these conclusions have been drawn by using bmv strain m1 (bmv-m1) and a related strain. here, the ability of the mps of five other natural bmv strains to mediate the movement of bmv-m1 in the absence of cp was tested. the mp of bmv m2 strain (bmv-m2) efficiently mediated the movement of cp-d ... | 2005 | 15784914 |
| yeast genome-wide screen reveals dissimilar sets of host genes affecting replication of rna viruses. | viruses are devastating pathogens of humans, animals, and plants. to further our understanding of how viruses use the resources of infected cells, we systematically tested the yeast single-gene-knockout library for the effect of each host gene on the replication of tomato bushy stunt virus (tbsv), a positive-strand rna virus of plants. the genome-wide screen identified 96 host genes whose absence either reduced or increased the accumulation of the tbsv replicon. the identified genes are involved ... | 2005 | 15883361 |
| the effects of b, k10, and ar chromosomes on the resistance of maize to viral infection. | studies were conducted to determine if accessory (b) chromosomes, the abnormal tenth (k10) chromosome or the aberrant ratio (ar) phenomenon of maize (zea mays l.) affect the resistance of the plants to viral infection. genetically similar stocks of maize with and without these elements were compared to determine what effect they would have on the plants response to brome mosaic virus (bmv), maize dwarf mosaic virus (mdmv), wheat streak mosaic virus (wsmv) and barley stripe mosaic virus (bsmv).-t ... | 1978 | 17248865 |
| coat protein-independent cell-to-cell movement of bromoviruses expressing brome mosaic virus movement protein with an adaptation-related amino acid change in the central region. | the movement protein (mp) of brome mosaic virus (bmv) depends on the coat protein (cp) to mediate the cell-to-cell movement of bmv and ccmv(b3a), a recombinant cowpea chlorotic mottle virus (ccmv) expressing bmv mp. previous studies identified gain-of-function mutations in the central region of bmv mp that enable ccmv(b3a) to adapt to a resistant host. this study demonstrates that all adaptation-related mps can partially or almost fully mediate the cell-to-cell movement of ccmv(b3a) and bmv with ... | 2005 | 15906103 |
| replication-independent expression of genome components and capsid protein of brome mosaic virus in planta: a functional role for viral replicase in rna packaging. | to begin elucidation of the relationship between brome mosaic virus (bmv) replication and encapsidation, we used a t-dna-based agrobacterium-mediated transient expression (agroinfiltration) system in nicotiana benthamiana leaves to express either individual or desired pairs of the three genomic rnas. the packaging competence of these rnas into virions formed by the transiently expressed coat protein (cp) was analyzed. we found that in the absence of a functional replicase, assembled virions cont ... | 2005 | 15936794 |
| two types of non-homologous rna recombination in brome mosaic virus. | non-homologous rna recombination is a process enabling the exchange of genetic material between various (related or unrelated) rna-based viruses. despite extensive investigations its molecular mechanism remains unclear. studies on genetic recombination in brome mosaic virus (bmv) have shown that local hybridization between genomic rnas induces frequent non-homologous crossovers. a detailed analysis of recombinant structures suggested that local complementary regions might be involved in two type ... | 2005 | 15940351 |
| a universal bmv-based rna recombination system--how to search for general rules in rna recombination. | at present, there is no doubt that rna recombination is one of the major factors responsible for the generation of new rna viruses and retroviruses. numerous experimental systems have been created to investigate this complex phenomenon. consequently, specific rna structural motifs mediating recombination have been identified in several viruses. unfortunately, up till now a unified model of genetic rna recombination has not been formulated, mainly due to difficulties with the direct comparison of ... | 2005 | 16002784 |
| brome mosaic virus 1a nucleoside triphosphatase/helicase domain plays crucial roles in recruiting rna replication templates. | positive-strand rna virus rna replication is invariably membrane associated and frequently involves viral proteins with nucleoside triphosphatase (ntpase)/helicase motifs or activities. brome mosaic virus (bmv) encodes two rna replication factors: 1a has a c-terminal ntpase/helicase-like domain, and 2a(pol) has a central polymerase domain. 1a accumulates on endoplasmic reticulum membranes, recruits 2a(pol), and induces 50- to 70-nm membrane invaginations (spherules) serving as rna replication co ... | 2005 | 16227294 |
| interaction between brome mosaic virus proteins and rnas: effects on rna replication, protein expression, and rna stability. | brome mosaic virus (bmv) rna replication has been examined in a number of systems, including saccharomyces cerevisiae. we developed an efficient t-dna-based gene delivery system using agrobacterium tumefaciens to transiently express bmv rnas in nicotiana benthamiana. the expressed rnas can systemically infect plants and provide material to extract bmv replicase that can perform template-dependent rna-dependent rna synthesis in vitro. we also expressed the four bmv-encoded proteins from nonreplic ... | 2005 | 16254357 |
| phosphorylation and interaction of the movement and coat proteins of brome mosaic virus in infected barley protoplasts. | the 3a movement protein (b3a) of brome mosaic virus (bmv) plays essential roles in the cell-to-cell movement of bmv. b3a is known to bind nucleic acids, to transport rna to neighbouring cells, and to form tubular structures. here, we tested the assumption that phosphorylation may be a mechanism that regulates b3a functions and showed that not only b3a but also the coat protein, bcp, was phosphorylated in bmv-infected barley protoplasts. both bcp and b3a were detected in a complex immunoprecipita ... | 2007 | 17680322 |
| trna-like structure regulates translation of brome mosaic virus rna. | for various groups of plant viruses, the genomic rnas end with a trna-like structure (tls) instead of the 3' poly(a) tail of common mrnas. the actual function of these tlss has long been enigmatic. recently, however, it became clear that for turnip yellow mosaic virus, a tymovirus, the valylated tls(tymv) of the single genomic rna functions as a bait for host ribosomes and directs them to the internal initiation site of translation (with n-terminal valine) of the second open reading frame for th ... | 2004 | 15047816 |
| ded1p, a conserved dexd/h-box translation factor, can promote yeast l-a virus negative-strand rna synthesis in vitro. | viruses are intracellular parasites that must use the host machinery to multiply. identification of the host factors that perform essential functions in viral replication is thus of crucial importance to the understanding of virus-host interactions. here we describe ded1p, a highly conserved dexd/h-box translation factor, as a possible host factor recruited by the yeast l-a double-stranded rna (dsrna) virus. we found that ded1p interacts specifically and strongly with gag, the l-a virus coat pro ... | 2004 | 15064363 |
| requirements for brome mosaic virus subgenomic rna synthesis in vivo and replicase-core promoter interactions in vitro. | based solely on in vitro results, two contrasting models have been proposed for the recognition of the brome mosaic virus (bmv) subgenomic core promoter by the replicase. the first posits that the replicase recognizes at least four key nucleotides in the core promoter, followed by an induced fit, wherein some of the nucleotides base pair prior to the initiation of rna synthesis (s. adkins and c. c. kao, virology 252:1-8, 1998). the second model posits that a short rna hairpin in the core promote ... | 2004 | 15163702 |
| sensitivity of brome mosaic virus rna1 replication to mutations in the 3' trna-like structure implies a requirement for sustained synthesis of replicase protein 1a. | the replication competence of a series of brome mosaic virus (bmv) rna1 variants with defined mutations in the 3' trna-like structure, previously characterized in vitro to be defective in minus-strand synthesis and several trna-associated functions, was analyzed in barley protoplasts. inocula containing wild type rnas2 and 3 and rna1 bearing either deltaknob or 5'psk mutation failed to replicate. two additional rna1 variants, each bearing either m4 or 5'aga mutation, resulted in detectable accum ... | 2006 | 16328142 |
| host deadenylation-dependent mrna decapping factors are required for a key step in brome mosaic virus rna replication. | the genomes of positive-strand rna [+rna] viruses perform two mutually exclusive functions: they act as mrnas for the translation of viral proteins and as templates for viral replication. a universal key step in the replication of +rna viruses is the coordinated transition of the rna genome from the cellular translation machinery to the viral replication complex. while host factors are involved in this step, their nature is largely unknown. by using the ability of the higher eukaryotic +rna viru ... | 2006 | 16352549 |
| the three-dimensional folding of the trna-like structure of tobacco mosaic virus rna. a new building principle applied twice. | the structure of the trna-like 3' terminus of tobacco mosaic virus (tmv) rna has been studied. a 3' -terminal fragment possessing the trna-like properties was probed with chemical modification and enzymatic digestions. a model of the secondary structure is proposed for the last 105 nucleotides. the corresponding region of other tobamoviral rnas can be folded in an identical secondary structure. a three-dimensional model for the trna-like structure is given which is compared with those proposed e ... | 1984 | 16453568 |
| a novel interaction of pokeweed antiviral protein with translation initiation factors 4g and iso4g: a potential indirect mechanism to access viral rnas. | pokeweed antiviral protein (pap) is a ribosome inactivating protein recognized primarily for its ability to depurinate the sarcin/ricin loop of the large rrna. studies have demonstrated that pap also depurinates other rna templates, such as human immunodeficiency virus-1 rna and brome mosaic virus rnas. however, the mechanism by which pap accesses viral rnas is not known. considering that pap was shown recently to bind the m(7)g of the cap structure, we speculated that pap may interact with othe ... | 2006 | 16493141 |
| development and evaluation of a real-time rt-pcr assay for quantification of cell-free human immunodeficiency virus type 2 using a brome mosaic virus internal control. | quantification of cell-free virus in plasma is important for monitoring disease progression and for assessing the response to antiretroviral therapy in both human immunodeficiency type 1 and type 2 (hiv-1, hiv-2) infections. although commercial assays suitable for hiv-1 quantification have been used for more than a decade, no commercial assays are yet available for the measurement of cell-free hiv-2. we have therefore developed a novel real-time rt-pcr assay which, unlike previously described 'i ... | 2006 | 16563526 |
| multicomponent rna plant virus infection derived from cloned viral cdna. | in vitro transcripts from mixtures of appropriate brome mosaic virus (bmv) cdna clones are infectious when inoculated onto barley plants. infectivity depends on in vitro transcription and on the presence of transcripts from clones of all three bmv genetic components. infectivity is destroyed by rnase after transcription, but it is insensitive to rnase before or to dnase after transcription. virion rnas from plants infected with cdna transcripts hybridize to bmv-specific probes and coelectrophore ... | 1984 | 16593527 |
| nanoparticle-templated assembly of viral protein cages. | self-assembly of regular protein surfaces around nanoparticle templates provides a new class of hybrid biomaterials with potential applications in medical imaging and in bioanalytical sensing. we report here the first example of efficiently self-assembled virus-like particles (vlps) having a brome mosaic virus protein coat and a functionalized gold core. the present study indicates that functionalized gold particles can initiate vlp assembly by mimicking the electrostatic behavior of the nucleic ... | 2006 | 16608253 |
| capsid protein gene and the type of host plant differentially modulate cell-to-cell movement of cowpea chlorotic mottle virus. | a study was undertaken to measure the rate of coat protein (cp) independent cell-to-cell movement of cowpea chlorotic mottle bromovirus (ccmv) in three different host plants. a ccmv rna3 variant in which the cp gene was substituted with enhanced green fluorescent protein (c3/deltacp-egfp) was coinoculated to three different host plants with transcripts of wild type rnas 1 and 2. comparative analysis of cell-to-cell movement monitored by the egfp expression at various days post inoculation reveal ... | 2006 | 16732474 |
| regulation of brome mosaic virus gene expression by restriction of initiation of protein synthesis. | the translation of total and individual brome mosaic virus (bmv) rnas was examined in a wheat germ cell-free system in the presence of various inhibitors. inhibitors of the initiation of polypeptide synthesis, e.g., potassium ions, 7-methylguanosine 5' -monophosphate, and aurintricarboxylic acid, were shown not only to inhibit overall bmv protein synthesis but also to change the ratio of bmv polypeptides synthesized. under conditions restrictive for initiation, the translation of nonstructural b ... | 1980 | 16789194 |
| inducible yeast system for viral rna recombination reveals requirement for an rna replication signal on both parental rnas. | to facilitate rna recombination studies, we tested whether saccharomyces cerevisiae, which supports brome mosaic virus (bmv) replication, also supports bmv rna recombination. yeast strains expressing bmv rna replication proteins 1a and 2a(pol) were engineered to transiently coexpress two independently inducible, overlapping, nonreplicating derivatives of bmv genomic rna3. b3delta3' lacked the coat protein gene and negative-strand rna promoter. b3delta5' lacked the positive-strand rna promoter an ... | 2006 | 16912283 |
| in vivo packaging of brome mosaic virus rna3, but not rnas 1 and 2, is dependent on a cis-acting 3' trna-like structure. | the four encapsidated rnas of brome mosaic virus (bmv; b1, b2, b3, and b4) contain a highly conserved 3' 200-nucleotide (nt) region encompassing the trna-like structure (tls) which is required for packaging in vitro (y. g. choi, t. w. dreher, and a. l. n. rao, proc. natl. acad. sci. usa 99:655-660, 2002). to validate these observations in vivo, we performed packaging assays using agrobacterium-mediated transient expression of rnas and coat protein (cp) (p. annamalai and a. l. n. rao, virology 33 ... | 2007 | 17005656 |