| conformational states of cowpea chlorotic mottle virus ribonucleic acid components. | the conditions determining conformational changes in the four ribonucleic acid components of cowpea chlorotic mottle virus have been studied. all four components have at least two electrophoretically separable conformers, the occurrence of which can be regulated by both monovalent and polyvalent cations. this phenomenon also occurs, in a much less striking way, in the ribonucleic acids of the two other members of the bromovirus group, brome mosaic virus and broad bean mottle virus. although spec ... | 1978 | 643624 |
| differential effect of 2-thiouracil on synthesis of two plant viruses in the same host. | in cowpea leaves singly or doubly infected with cowpea chlorotic mottle virus (ccmv) and/or southern bean mosaic virus (sbmv), treatment with 2-thiouracil increased the accumulation of ccmv particles and strongly decreased the accumulation of sbmv particles. thiouracil prevented the usual inhibition of synthesis of ccmv particles at about 6 days after inoculation, and 2-3 times as many ccmv particles accumulated as in water-treated plants. a single treatment of thiouracil 48 h before, at the tim ... | 1977 | 870449 |
| a hybrid plant rna virus made by transferring the noncapsid movement protein from a rod-shaped to an icosahedral virus is competent for systemic infection. | for many plant rna viruses, multiple viral gene products, including noncapsid movement proteins and capsid proteins, contribute to the spread of infection within plants. the extent to which these factors interact to support infection spread is not known, but, for movement protein mutants of certain viruses, the inability of coinoculated "helper" viruses to complement defective movement has suggested a possible requirement for coadaptation between noncapsid movement proteins and other virus facto ... | 1992 | 1495969 |
| the nucleotide sequence and genome organization of the rna2 and rna3 segments in broad bean mottle virus. | complete nucleotide sequences of broad bean mottle virus (bbmv) genomic rnas 2 and 3 were determined. they consist of 2811 and 2293 nucleotides, respectively. both rnas are caped and, unlike in other tricornaviruses, both initiate with an a residue. bbmv rna2 is monocistronic and encodes an 815 amino acid 2a protein, whereas rna3 is dicistronic, encoding for a 295 amino acid 3a protein and for the 190 amino acid coat protein. a central, 423 amino acid 2a protein core region is highly homologous ... | 1992 | 1546462 |
| the requirement for a 5' stem-loop structure in brome mosaic virus replication supports a new model for viral positive-strand rna initiation. | sequences with strong similarity to internal control regions 1 and 2 (icr1 and -2; a and b boxes) of trna genes are found at the 5' termini of the genomic rnas of brome mosaic virus (bmv) and other plant viruses. the functionality of these motifs was studied by introducing point mutations into the icr2-like sequence of prna-2 m/s, a bmv rna-2 deletion mutant that replicates in the presence of rnas-1 and -2 but does not encode a functional viral protein. the accumulation of positive-strand progen ... | 1992 | 1731107 |
| substantial portions of the 5' and intercistronic noncoding regions of cowpea chlorotic mottle virus rna3 are dispensable for systemic infection but influence viral competitiveness and infection pathology. | cowpea chlorotic mottle virus (ccmv) has a tripartite, positive strand rna genome. genomic rna3 (2.2 kb) encodes the 3a nonstructural protein and the coat protein, which are dispensable for viral rna synthesis in protoplasts, but required for systemic infection of whole plants. in protoplasts, portions of the 5' and intercistronic noncoding regions of ccmv rna3 are also dispensable for rna3 replication and for transcription of the subgenomic coat protein mrna. to determine whether these noncodin ... | 1992 | 1736532 |
| the nucleotide sequence and genome organization of the rna-1 segment in two bromoviruses: broad bean mottle virus and cowpea chlorotic mottle virus. | the complete nucleotide sequences of the rna-1 segments in broad bean mottle virus (bbmv) and cowpea chlorotic mottle virus (ccmv) were determined. bbmv rna-1 consists of 3158 nucleotides and ccmv rna-1 has 3171 nucleotides. both bbmv and ccmv rna-1 are capped at the 5' end but, unlike in other tricornaviruses, bbmv rna-1 initiates with an a residue. both bbmv and ccmv rna-1 are monocistronic encoding for highly homologous 1a proteins of 966 and 958 amino acids, respectively. the highest homolog ... | 1991 | 1962437 |
| nucleotide sequence of tomato aspermy virus rna 2. | rna 2 of the v strain of tomato aspermy virus (tav) consists of 3074 nucleotides and contains one open reading frame of 2487 nucleotides. thus, it resembles rna 2 of cucumber mosaic virus (cmv) strains q and fny (62% identical to both), brome mosaic virus (42% identical) and cowpea chlorotic mottle virus (40% identical). in comparisons between amino acid sequences, three different regions of similarity could be distinguished. these were the central part (amino acids 224 to 757 for v-tav), which ... | 1991 | 2016592 |
| use of bromovirus rna3 hybrids to study template specificity in viral rna amplification. | brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) are related positive-strand rna viruses with genomes divided among rnas 1, 2, and 3. rnas 1 and 2 encode the viral rna replication factors, which share extensive conservation with proteins encoded by the animal alphaviruses and diverse plant viruses. in barley protoplasts, ccmv rnas 1 and 2 support high but distinguishable amplification of either bmv rna3 (b3) or ccmv rna3 (c3), while bmv rnas 1 and 2 show even greater discriminat ... | 1991 | 2041089 |
| use of bromovirus rna2 hybrids to map cis- and trans-acting functions in a conserved rna replication gene. | brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) are related positive-strand rna viruses with tripartite genomes. rna replication by either virus requires genomic rnas 1 and 2, which encode protein 1a and the polymeraselike, 94-kilodalton 2a protein, respectively. proteins 1a and 2a share extensive sequence similarity with proteins encoded by a wide range of other positive-strand rna viruses of animals and plants. heterologous combinations of bmv and ccmv rnas 1 and 2 do not sup ... | 1990 | 2293671 |
| cis-acting sequences required for in vivo amplification of genomic rna3 are organized differently in related bromoviruses. | cowpea chlorotic mottle virus (ccmv) is a positive-strand rna virus that infects dicotyledonous plants. the genome comprises three capped rnas: rna1 (3.2 kb), rna2 (2.9 kb), and rna3 (2.1 kb). cis-acting sequences required for amplification in vivo were explored for rna3, which does not contribute trans-acting factors to viral rna replication. using a ccmv cdna expression system, deletions throughout rna3 were constructed and tested for successful replication in barley protoplasts coinoculated w ... | 1990 | 2305551 |
| regeneration of a functional rna virus genome by recombination between deletion mutants and requirement for cowpea chlorotic mottle virus 3a and coat genes for systemic infection. | rnas 1 and 2 of the tripartite cowpea chlorotic mottle virus (ccmv) genome are sufficient for rna replication in protoplasts, whereas systemic infection of cowpea plants additionally requires rna3, which encodes the 3a noncapsid protein and coat protein. by using biologically active ccmv cdna clones, we find that deletions in either rna3 gene block systemic infection. thus, though some plant rna viruses are able to spread systemically without encapsidation, both the coat and 3a genes are require ... | 1990 | 2308940 |
| sequence of cowpea chlorotic mottle virus rnas 2 and 3 and evidence of a recombination event during bromovirus evolution. | the genomic sequence of cowpea chlorotic mottle virus (ccmv) was completed by sequencing biologically active cdna clones of ccmv rna2 (2774 bases) and rna3 (2173 bases). while only the central core of the encoded 94-kda ccmv 2a protein contains features conserved among known and putative rna replication proteins from many viruses, both flanking regions of ccmv 2a show substantial similarity to the corresponding protein of the related brome mosaic virus (bmv). the 3a proteins of ccmv and bmv, imp ... | 1989 | 2773323 |
| virus-ribosome complexes from cell-free translation systems supplemented with cowpea chlorotic mottle virus particles. | when particles of cowpea chlorotic mottle virus (ccmv) were added to cell-free extracts from wheat germ, the encapsidated viral genome was translated into polypeptides similar to the translation products specified by unencapsidated viral rna (as shown before by m.j. brisco, r. hull, and t.m.a. wilson, 1986, virology 148, 210-217). the rate of protein synthesis observed upon addition of virus particles was much slower than that of extracted rna and the quantity of protein formed was only 10% of t ... | 1989 | 2909987 |
| binding of cowpea chlorotic mottle virus to cowpea protoplasts and relation of binding to virus entry and infection. | cowpea chlorotic mottle virus (ccmv) and cowpea protoplasts were used to study initial interactions between virus and protoplast. protoplasts and virus were incubated under varying conditions of temperature, ph, ionic strength, and the presence of added compounds. both the amount of 35s-labeled virus bound to protoplasts and the percentage of infected cells were determined. at 0 and 25 degrees the amount of virus associated with protoplasts increased with the amount of virus added. with inoculum ... | 1988 | 3363871 |
| infectious in vitro transcripts from cowpea chlorotic mottle virus cdna clones and exchange of individual rna components with brome mosaic virus. | complete cdna copies of genomic rna1, rna2, and rna3 of cowpea chlorotic mottle virus (ccmv) were cloned 1 base downstream from a t7 rna polymerase promoter. the mixture of capped in vitro transcripts from all three clones produced normal ccmv infections in barley protoplasts and cowpea plants. by using transcripts from these clones and from a similar set of biologically active clones of the related brome mosaic virus (bmv), all possible single component exchanges between the bmv and ccmv tripar ... | 1988 | 3418781 |
| structure and infectivity of picornaviral rna encapsidated by cowpea chlorotic mottle virus protein. | poliovirus and mengo virus rna were shown to associate efficiently with cowpea chlorotic mottle virus protein to form pseudovirions. the sedimentation coefficient for the pseudovirions was similar to that of poliovirus, and electron microscope observations showed the mengo pseudovirions to be similar in size to mengo virus. such pseudovirions were infectious and were more resistant to ribonuclease than viral rna; however, under our assay conditions, their infectivity was about equal to that of v ... | 1973 | 4128376 |
| minor protein components in cowpea chlorotic mottle virus and satellite of tobacco necrosis virus. | | 1974 | 4414688 |
| the infection of tobacco protoplasts with cowpea chlorotic mottle virus and its rna. | | 1973 | 4584931 |
| specificity of the actinomycin-d-sensitive function of some rna plant viruses. | the actinomycin-d(amd)-sensitive step of replication of three plant viruses - cowpea chlorotic mottle virus (ccmv), cowpea mosaic virus, and the cowpea strain of tobacco mosaic virus - in cowpea was specific for each virus. different combinations of the viruses were examined in which leaves were inoculated with one virus and incubated for 48 h until multiplication was almost resistant to amd. at that time, the same leaves were inoculated with a different virus and the ability of amd to inhibit m ... | 1984 | 6735660 |
| complete nucleotide sequences of the coat protein messenger rnas of brome mosaic virus and cowpea chlorotic mottle virus. | the nucleotide sequences of the subgenomic coat protein messengers (rna4's) of two related bromoviruses, brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv), have been determined by direct rna and cdna sequencing without cloning. bmv rna4 is 876 b long including a 5' noncoding region of nine nucleotides and a 3' noncoding region of 300 nucleotides. ccmv rna 4 is 824 b long, including a 5' noncoding region of 10 nucleotides and a 3' noncoding region of 244 nucleotides. the encoded c ... | 1982 | 6895941 |
| the rnas of bromoviruses: 3'-terminal sequences of the four brome mosaic virus rnas and comparison with cowpea chlorotic mottle virus rna 4. | | 1980 | 7389920 |
| bromovirus movement protein genes play a crucial role in host specificity. | monocot-adapted brome mosaic virus (bmv) and dicot-adapted cowpea chlorotic mottle virus (ccmv) are closely related bromoviruses with tripartite rna genomes. although rnas 1 and 2 together are sufficient for rna replication in protoplasts, systemic infection also requires rna3, which encodes the coat protein and the nonstructural 3a movement protein. we have previously shown with bromoviral reassortants that host specificity determinants in both viruses are encoded by rna3 as well as by rna1 and ... | 1993 | 7682628 |
| structures of the native and swollen forms of cowpea chlorotic mottle virus determined by x-ray crystallography and cryo-electron microscopy. | rna-protein interactions stabilize many viruses and also the nucleoprotein cores of enveloped animal viruses (e.g. retroviruses). the nucleoprotein particles are frequently pleomorphic and generally unstable due to the lack of strong protein-protein interactions in their capsids. principles governing their structures are unknown because crystals of such nucleoprotein particles that diffract to high resolution have not previously been produced. cowpea chlorotic mottle virions (ccmv) are typical o ... | 1995 | 7743132 |
| in vitro assembly of cowpea chlorotic mottle virus from coat protein expressed in escherichia coli and in vitro-transcribed viral cdna. | the small spherical plant virus, cowpea chlorotic mottle virus (ccmv), provides an ideal system to examine spherical virus assembly. we have modified the ccmv in vitro assembly system to produce virions from coat protein expressed in escherichia coli and viral rna transcribed in vitro from full-length cdnas. examination of the in vitro-assembled particles with cryoelectron microscopy and image reconstruction techniques demonstrates that the particles are indistinguishable from plant purified par ... | 1995 | 7886952 |
| the nucleotide sequence of citrus leaf rugose ilarvirus rna-2. | the nucleotide sequence of citrus leaf rugose ilarvirus (cilrv) rna-2 consists of 2990 nucleotides and contains one open reading frame (orf) which encodes a deduced translation product of 832 amino acids with a calculated m(r) of 95,501 (95k). the 5' terminus of the rna has a m7gppp cap. both the nucleotide sequence of cilrv rna-2 and its translated polypeptide share homologies with the nucleotide sequence and translated polypeptide, respectively, of rna-2 of alfalfa mosaic virus (almv). the hom ... | 1994 | 7931176 |
| bromovirus rna replication and transcription require compatibility between the polymerase- and helicase-like viral rna synthesis proteins. | the positive-strand rna bromoviruses encode two nonstructural proteins, 1a and 2a, involved in rna-dependent rna replication. these proteins have extensive sequence similarities with methyltransferase, helicase, and polymerase proteins of other plant and animal viruses. 1a and 2a can also form a complex in vitro. to explore whether 1a-2a interaction is required for rna replication in vivo, we reassorted the 1a and 2a genes from two different bromoviruses, brome mosaic virus (bmv) and cowpea chlo ... | 1993 | 8230440 |
| in vitro destabilization of plant viruses and cdna synthesis. | dna copies of a wide range of rna viruses can be made by the direct addition of appropriately treated, purified virus particles to a reverse transcription reaction. therefore, many problems associated with rna isolation can be circumvented. virus particles can be sufficiently destabilized by adjustments of salt content, buffer, ph or by the use of physical force supplied by a freeze/thaw cycle so that rna in sufficient quantity and physical condition is available for the synthesis of in some cas ... | 1993 | 8263116 |
| the polymerase-like core of brome mosaic virus 2a protein, lacking a region interacting with viral 1a protein in vitro, maintains activity and 1a selectivity in rna replication. | brome mosaic virus (bmv), a member of the alphavirus-like super-family of positive-strand rna viruses, encodes two proteins required for viral rna replication: 1a and 2a. 1a contains m7g methyltransferase- and helicase-like domains, while 2a contains a polymerase (pol)-like core flanked by n- and c-terminal extensions. genetic studies show that bmv rna replication requires 1a-2a compatibility implying direct or indirect 1a-2a interaction in vivo. in vitro, la interacts with the n-terminal 125-am ... | 1996 | 8676500 |
| analysis of a salt stable mutant of cowpea chlorotic mottle virus. | an understanding of virion assembly and disassembly requires a detailed understanding of the protein-protein and protein-nucleic acid interactions which stabilize the virion. we have characterized a mutant of cowpea chlorotic mottle virus (ccmv) that is altered in virion stability. the mutant virions resist disassembly in 1.0 m nacl, ph 7.5, whereas the wild-type virions completely disassociate into rna and capsid protein components. sequence analysis of the mutant coat protein gene identified a ... | 1996 | 8806492 |
| a single codon change in a conserved motif of a bromovirus movement protein gene confers compatibility with a new host. | brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) are closely related bromoviruses with tripartite rna genomes, but distinct host ranges: bmv systemically infects the monocot barley, while ccmv systemically infects the dicot cowpea. we have previously shown that in approximately 10% of inoculated cowpea plants, a ccmv hybrid [ccmv(b3a)] with the 3a cell-to-cell movement protein gene replaced by that of cowpea-nonadapted bmv directs systemic infections, which are caused by seconda ... | 1996 | 8806564 |
| structure-based rationale for the rescue of systemic movement of brome mosaic virus by spontaneous second-site mutations in the coat protein gene. | we describe spontaneous second-site reversions within the coat protein open reading frame that rescue the systemic-spread phenotype and increase virion stability of a mutant of brome mosaic virus. based on the crystal structure of the related cowpea chlorotic mottle virus, we show that the modified residues are spatially clustered to affect the formation of hexamers and pentamers and therefore virion stability. | 1997 | 9032390 |
| the structure of cucumber mosaic virus: cryoelectron microscopy, x-ray crystallography, and sequence analysis. | the three-dimensional structure of cucumber mosaic virus (cmv) was analyzed at 23 a resolution by cryoelectron microscopy and image reconstruction, demonstrating structural similarity to cowpea chlorotic mottle virus (ccmv), another member of the bromoviridae family. the cmv structure was determined at 8 a resolution by x-ray crystallography with phases determined by single isomorphous replacement and refined by fivefold noncrystallographic symmetry averaging. the x-ray structure agreed with the ... | 1997 | 9185592 |
| effects of coat protein mutations and reduced movement protein expression on infection spread by cowpea chlorotic mottle virus and its hybrid derivatives. | previously we have reported that the essential 3a movement gene of icosahedral cowpea chlorotic mottle virus (ccmv) can be functionally replaced by the 30-kda movement gene of rod-shaped sunn-hemp mosaic virus (shmv). because plant rna viruses differ in requiring or not requiring coat protein for systemic infection, we have now investigated whether systemic spread by this ccmv/shmv hybrid is dependent on its ccmv coat protein as well as its shmv movement protein. we find that either deletion or ... | 1997 | 9185600 |
| molecular studies on bromovirus capsid protein. iii. analysis of cell-to-cell movement competence of coat protein defective variants of cowpea chlorotic mottle virus. | to determine whether the role of coat protein (cp) in cell-to-cell movement of dicot-adapted cowpea chlorotic mottle bromovirus (ccmv) is distinct from that of monocot-adapted brome mosaic bromovirus (bmv), two reporter genes, beta-glucuronidase (gus) and enhanced green fluorescent protein (egfp), were substituted for the cp in a biologically active clone of ccmv rna3 (c3). primary leaves of nicotiana benthamiana, chenopodium quinoa, and cowpea were co-inoculated with wild-type (wt) ccmv rna 1 a ... | 1997 | 9191853 |
| analysis of the interaction of viral rna replication proteins by using the yeast two-hybrid assay. | the yeast two-hybrid system has been a useful tool in the genetic evaluation of protein-protein interactions. however, the biological relevance of these two-hybrid interactions to viral positive-strand rna replication has not been demonstrated. the brome mosaic virus (bmv) system has been characterized extensively both genetically and biochemically, providing numerous mutations in the bmv 1a helicase-like and 2a polymerase-like proteins. we have tested wild-type 1a and 18 insertion mutations of ... | 1997 | 9311832 |
| iris explorer software for radial-depth cueing reovirus particles and other macromolecular structures determined by cryoelectron microscopy and image reconstruction. | structures of biological macromolecules determined by transmission cryoelectron microscopy (cryo-tem) and three-dimensional image reconstruction are often displayed as surface-shaded representations with depth cueing along the viewed direction (z cueing). depth cueing to indicate distance from the center of virus particles (radial-depth cueing, or r cueing) has also been used. we have found that a style of r cueing in which color is applied in smooth or discontinuous gradients using the iris exp ... | 1997 | 9361260 |
| molecular studies on bromovirus capsid protein. iv. coat protein exchanges between brome mosaic and cowpea chlorotic mottle viruses exhibit neutral effects in heterologous hosts. | two members of the bromovirus group, brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv), selectively infect barley and cowpea, respectively, and also differ in their ability to systemically infect a common permissive host, chenopodium quinoa. ccmv is confined to inoculated leaves of c. quinoa, whereas bmv causes rapid systemic mottling. to examine whether host-specific determinants for systemic movement of bmv and ccmv in each of these hosts are localized in the coat protein (cp), ... | 1997 | 9400617 |
| characterization of the nucleic acid binding properties of tomato spotted wilt virus nucleocapsid protein. | tomato spotted wilt tospovirus (tswv) is the type member of the plant-infecting viruses of the genus tospovirus in the family bunyaviridae. the three tswv rnas are encapsidated with nucleocapsid (n) protein to form ribonucleoprotein (rnp) which serves as the template for viral transcription and replication. regions of the open reading frame coding for the n protein on the small (s) rna were subcloned into pet protein expression vectors and expressed in escherichia coli bl21 (de3) cells. full-len ... | 1998 | 9705250 |
| subgenomic rna promoters dictate the mode of recognition by bromoviral rna-dependent rna polymerases. | both the brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) rna-dependent rna polymerases (rdrps) were found to recognize the bmv core subgenomic promoter in the same manner, requiring specific functional groups at positions -17, -14, -13, and -11 relative to the subgenomic initiation site (+1). for ccmv subgenomic rna synthesis, both rdrps required the same nucleotides and four additional nucleotides at positions -20, -16, -15, and -10. the -20 nucleotide is partially responsible ... | 1998 | 9875310 |
| identification of a cell surface protein from crandell feline kidney cells that specifically binds aleutian mink disease parvovirus. | aleutian mink disease parvovirus (adv) is the etiological agent of aleutian disease of mink. the acute disease caused by adv consists of permissive infection of alveolar type ii cells that results in interstitial pneumonitis. the permissive infection is experimentally modeled in vitro by infecting crandell feline kidney (crfk) cells with a tissue culture-adapted isolate of adv, adv-g. adv-g vp2 empty virions expressed in a recombinant baculovirus system were analyzed for the ability to bind to t ... | 1999 | 10196278 |
| evolutionarily related sindbis-like plant viruses maintain different levels of population diversity in a common host. | the levels of population diversity of three related sindbis-like plant viruses, tobacco mosaic virus (tmv), cucumber mosaic virus (cmv), and cowpea chlorotic mottle virus (ccmv), in infections of a common host, nicotiana benthamiana, established from genetically identical viral rna were examined. despite probably having a common evolutionary ancestor, the three viruses maintained different levels of population diversity. cmv had the highest levels of diversity, tmv had an intermediate level of d ... | 2000 | 10708428 |
| the structure of cucumber mosaic virus and comparison to cowpea chlorotic mottle virus. | the structure of cucumber mosaic virus (cmv; strain fny) has been determined to a 3.2-a resolution using x-ray crystallography. despite the fact that cmv has only 19% capsid protein sequence identity (34% similarity) to cowpea chlorotic mottle virus (ccmv), the core structures of these two members of the bromoviridae family are highly homologous. as suggested by a previous low-resolution structural study, the 305-a diameter (maximum) of cmv is approximately 12 a larger than that of ccmv. in ccmv ... | 2000 | 10906212 |
| bromovirus movement protein conditions for the host specificity of virus movement through the vascular system and affects pathogenicity in cowpea. | previously, we reported that ccmv(b3a), a hybrid of bromovirus cowpea chlorotic mottle virus (ccmv) with the 3a cell-to-cell movement protein (mp) gene replaced by that of cowpea-nonadapted bromovirus brome mosaic virus (bmv), can form small infection foci in inoculated cowpea leaves, but that expansion of the foci stops between 1 and 2 days postinoculation. to determine whether the lack of systemic movement of ccmv(b3a) is due to restriction of local spread at specific leaf tissue interfaces, w ... | 2000 | 11059486 |
| mechanism of capsid assembly for an icosahedral plant virus. | capsids of spherical viruses share a common architecture: an icosahedral arrangement of identical proteins. we suggest that there may be a limited number of common assembly mechanisms for such viruses. previous assembly mechanisms were proposed on the basis of virion structure but were not rigorously tested. here we apply a rigorous analysis of assembly to cowpea chlorotic mottle virus (ccmv), a typical, small, positive-strand rna virus. the atomic resolution structure of ccmv revealed an interl ... | 2000 | 11080492 |
| site-specific single amino acid changes to lys or arg in the central region of the movement protein of a hybrid bromovirus are required for adaptation to a nonhost. | a hybrid cowpea chlorotic mottle virus (ccmv) [ccmv(b3a)] in which the ccmv 3a movement protein gene is replaced by the 3a (b3a) gene of brome mosaic virus cannot infect cowpea systemically. previously, analysis of rna3 cdna clones constructed from cowpea-adapted mutants derived from ccmv(b3a) revealed that a single codon change in the b3a gene allowed ccmv(b3a) to infect cowpea systemically. in this study, to extend the analysis of the ccmv(b3a) adaptation mechanism, we directly sequenced b3a g ... | 2001 | 11145888 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| interaction with capsid protein alters rna structure and the pathway for in vitro assembly of cowpea chlorotic mottle virus. | viruses use sophisticated mechanisms to allow the specific packaging of their genome over that of host nucleic acids. we examined the in vitro assembly of the cowpea chlorotic mottle virus (ccmv) and observed that assembly with viral rna follows two different mechanisms. initially, ccmv capsid protein (cp) dimers bind rna with low cooperativity and form virus-like particles of 90 cp dimers and one copy of rna. longer incubation reveals a different assembly path. at a stoichiometry of about ten c ... | 2004 | 14672655 |
| 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 |
| 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 |
| normal mode based flexible fitting of high-resolution structure into low-resolution experimental data from cryo-em. | a new method for the flexible fitting of high-resolution structures into low-resolution maps of macromolecular complexes from electron microscopy has been recently described in applications to simulated electron density maps. this method uses a linear combination of low-frequency normal modes in an iterative manner to deform the structure optimally to conform to the low-resolution electron density map. gradient-following techniques in the coordinate space of collective normal modes are used to o ... | 2004 | 15450300 |
| 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 |
| deletion of highly conserved arginine-rich rna binding motif in cowpea chlorotic mottle virus capsid protein results in virion structural alterations and rna packaging constraints. | the n-proximal region of cowpea chlorotic mottle virus (ccmv) capsid protein (cp) contains an arginine-rich rna binding motif (arm) that is also found in the cps of other members of bromoviridae and in other rna binding proteins such as the tat and rev proteins of human immunodeficiency virus. to assess the critical role played by this motif during encapsidation, a variant of ccmv rna3 (c3) precisely lacking the arm region (c3/delta919) of its cp gene was constructed. the biology and the compete ... | 2005 | 15731222 |
| 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 |
| 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 |
| normal mode calculations of icosahedral viruses with full dihedral flexibility by use of molecular symmetry. | the study of the dynamics and thermodynamics of small icosahedral virus capsids is an active field of research. normal mode analysis is one of the computational tools that can provide important insights into the conformational changes of the virus associated with cell entry or caused by changing of the physicochemical environment. normal mode analysis of virus capsids has been limited due to the size of these systems, which often exceed 50,000 residues. here we present the first normal mode calc ... | 2005 | 15922356 |
| electrostatic properties of cowpea chlorotic mottle virus and cucumber mosaic virus capsids. | electrostatic properties of cowpea chlorotic mottle virus (ccmv) and cucumber mosaic virus (cmv) were investigated using numerical solutions to the poisson-boltzmann equation. experimentally, it has been shown that ccmv particles swell in the absence of divalent cations when the ph is raised from 5 to 7. cmv, although structurally homologous, does not undergo this transition. an analysis of the calculated electrostatic potential confirms that a strong electrostatic repulsion at the calcium-bindi ... | 2006 | 16278831 |
| 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 |
| effect of cordycepin triphosphate on in vitro rna synthesis by plant viral replicases. | in vitro rna synthesis by tobacco mosaic virus and cowpea chlorotic mottle virus replicase were inhibited by cordycepin triphosphate. inhibition could be overcome with higher concentrations of atp in assay mixtures but not with utp. products synthesized in vitro by tobacco mosaic virus rna replicase in the presence of inhibitor revealed replicative form but not replicative intermediate rnas. these results suggest that cordycepin triphosphate competes specifically with atp and results in prematur ... | 1979 | 16789174 |
| expression and self-assembly of cowpea chlorotic mottle virus-like particles in pseudomonas fluorescens. | coat protein of the cowpea chlorotic mottle virus (ccmv), a plant bromovirus, has been expressed in a soluble form in a prokaryote, pseudomonas fluorescens, and assembled into virus-like particles (vlps) in vivo that were structurally similar to the native ccmv particles derived from plants. the ccmv vlps were purified by peg precipitation followed by separation on a sucrose density gradient and analyzed by size exclusion chromatography, uv spectrometry, and transmission electron microscopy. dna ... | 2007 | 17113675 |
| biodistribution studies of protein cage nanoparticles demonstrate broad tissue distribution and rapid clearance in vivo. | protein cage nanoparticles have the potential to serve as multifunctional cell targeted, imaging and therapeutic platforms for broad applications in medicine. however, before they find applications in medicine, their biocompatibility in vivo needs to be demonstrated. we provide here baseline biodistribution information of two different spherical protein cage nanoplatforms, the 28 nm viral cowpea chlorotic mottle virus (ccmv) and the 12 nm heat shock protein (hsp) cage. in naive and immunized mic ... | 2007 | 18203438 |
| double infection of tobacco protoplasts with brome mosaic virus and cowpea chlorotic mottle virus. | mixed infections of tobacco protoplasts with cowpea chlorotic mottle virus (ccmv) and brome mosaic virus (bmv) have been studied. fluorescent antibody staining showed that capsids of both viruses were made in doubly infected protoplasts but only infectious bmv could be recovered, i.e., bmv dominated in mixed infections and prevented synthesis of infectious ccmv. healthy protoplasts could be infected after several hours in culture but the susceptibility to infection decreased with time in culture ... | 1980 | 18631680 |
| rna-dependent rna polymerase isolated from cowpea chlorotic mottle virus-infected cowpeas is specific for bromoviral rna. | an rna-dependent rna polymerase activity capable of synthesizing full length double-stranded rna products only in the presence of bromoviral rna templates has been isolated from cowpea chlorotic mottle virus (ccmv)-infected cowpeas. no comparable discrete products were obtained when a nonbromoviral (cowpea mosaic virus) rna was used as template. heterodisperse, ribonuclease-sensitive products were obtained in reactions catalyzed by similar extracts from mock-inoculated (uninfected) plants in the ... | 1984 | 18639798 |
| the semipermeability of simple spherical virus capsids. | hydrogen-ion titration curves are reported for tomato bushy stunt virus, two strains of cowpea chlorotic mottle virus, and turnip crinkle virus, with particular attention to the hysteresis loops associated with the swelling and contraction of virions. there appears to be an archetypal shape of hysteresis loops, which is shared by viruses in several groups, suggestive of many intermediate states in the swelling of any one particle. in contrast, eggplant mosaic virus behaves as if its protein caps ... | 1984 | 18639804 |
| swelling of isometric and of bacilliform plant virus nucleocapsids is required for virus-specific protein synthesis in vitro. | encapsidated rna of cowpea chlorotic mottle virus (ccmv), brome mosaic virus (bmv), alfalfa mosaic virus, and southern bean mosaic virus can act as templates for protein synthesis when preswollen virions are added to a wheat germ extract, or when unswollen virions swell in the extract. encapsidated rna of turnip yellow mosaic virus, whose particles are unlikely to swell under the conditions used here, did not act as a template. ccmv and bmv, swollen in the extract, gave relatively more rna 1 and ... | 1986 | 18640565 |
| inoculation of protoplasts with viruses by electroporation. | optimal conditions for electroporation have been determined using inoculation of brome mosaic virus (bmv) and cowpea chlorotic mottle virus (ccmv) and its rna into protoplasts of nicotiana tabacum and n. plumbaginifolia. the most satisfactory medium was 0.5-0.7 m mannitol; calcium ions were toxic and other electrolytes were not helpful during electroporation. brief pulses (ca. 10 microsec) were less destructive to the protoplasts than longer ones (ca. 10 msec) and gave high percentage infections ... | 1987 | 18644555 |
| a simple technique for separation of cowpea chlorotic mottle virus from cucumber mosaic virus in natural mixed infections. | a simple technique was developed to separate cowpea chlorotic mottle virus (ccmv) from cucumber mosaic virus (cmv) in natural mixed infections. sap from cowpea leaves infected naturally with a mixture of ccmv and cmv was inoculated mechanically on the first tri-foliolate leaf of cowpea seedlings. both inoculated and non-inoculated upper leaves were sampled 3 or 8 days post-inoculation and tested by reverse transcription polymerase chain reaction (rt-pcr) using primers specific to ccmv and cmv. r ... | 2008 | 18755217 |
| small-scale isolation of viral rna-dependent rna polymerase from protoplasts inoculated with in vitro transcripts. | cowpea chlorotic mottle virus (ccmv) replicated in tobacco suspension cell protoplasts inoculated with in vitro transcripts of ccmv rna1, 2, and 3. ccmv rna-dependent rna polymerase (rdrp) isolated from these protoplasts specifically recognized ccmv and brome mosaic virus (bmv) subgenomic rna promoters and directed in vitro rna synthesis in a manner indistinguishable from ccmv rdrp more laboriously isolated from systemically infected cowpea leaves. omission of ccmv rna3 from the protoplast inocu ... | 2001 | 18944031 |
| mechanisms of size control and polymorphism in viral capsid assembly. | we simulate the assembly dynamics of icosahedral capsids from subunits that interconvert between different conformations (or quasi-equivalent states). the simulations identify mechanisms by which subunits form empty capsids with only one morphology but adaptively assemble into different icosahedral morphologies around nanoparticle cargoes with varying sizes, as seen in recent experiments with brome mosaic virus (bmv) capsid proteins. adaptive cargo encapsidation requires moderate cargo-subunit i ... | 2008 | 18950240 |
| capsid protein of cowpea chlorotic mottle virus is a determinant for vector transmission by a beetle. | cowpea chlorotic mottle virus (ccmv) is a bromovirus transmitted by species of chrysomelid beetles, including the spotted cucumber beetle, diabrotica undecimpunctata howardii barber. an experimental system was set up to identify the viral determinant(s) of the beetle transmission of ccmv. nicotiana clevelandii was selected as an experimental plant host because it supports the replication and accumulation of both ccmv and a second member of the family bromoviridae, cucumber mosaic virus (cmv). us ... | 2010 | 19828763 |
| atomistic modeling of the low-frequency mechanical modes and raman spectra of icosahedral virus capsids. | we describe a technique for calculating the low-frequency mechanical modes and frequencies of a large symmetric biological molecule where the eigenvectors of the hessian matrix are determined with full atomic detail. the method, which follows order n methods used in electronic structure theory, determines the subset of lowest-frequency modes while using group theory to reduce the complexity of the problem. we apply the method to three icosahedral viruses of various t numbers and sizes; the human ... | 2010 | 20365606 |
| virus hybrids as nanomaterials for biotechnology. | the current review describes advances in the field of bionanotechnology in which viruses are used to fabricate nanomaterials. viruses are introduced as protein cages, scaffolds, and templates for the production of biohybrid nanostructured materials where organic and inorganic molecules are incorporated in a precise and a controlled fashion. genetic engineering enables the insertion or replacement of selected amino acids on virus capsids for uses from bioconjugation to crystal growth. the variety ... | 2010 | 20688511 |
| a crystallographic approach to structural transitions in icosahedral viruses. | viruses with icosahedral capsids, which form the largest class of all viruses and contain a number of important human pathogens, can be modelled via suitable icosahedrally invariant finite subsets of icosahedral 3d quasicrystals. we combine concepts from the theory of 3d quasicrystals, and from the theory of structural phase transformations in crystalline solids, to give a framework for the study of the structural transitions occurring in icosahedral viral capsids during maturation or infection. ... | 2011 | 21611828 |
| using polymer conformation to control architecture in semiconducting polymer/viral capsid assemblies. | cowpea chlorotic mottle virus is a single-stranded rna plant virus with a diameter of 28 nm. the proteins comprising the capsid of this virus can be purified and reassembled either by themselves to form hollow structures or with polyanions such as double-stranded dna or single-stranded rna. depending on ph and ionic strength, a diverse range of structures and shapes can form. the work presented here focuses on using these proteins to encapsulate a fluorescent polyanionic semiconducting polymer, ... | 2011 | 21942298 |
| packaging and structural phenotype of brome mosaic virus capsid protein with altered n-terminal β-hexamer structure. | the first 45 amino acid region of brome mosaic virus (bmv) capsid protein (cp) contains rna binding and structural domains that are implicated in the assembly of infectious virions. one such important structural domain encompassing amino acids 28qpviv32, highly conserved between bmv and cowpea chlorotic mottle virus (ccmv), exhibits a β-hexamer structure. in this study we report that alteration of the β-hexamer structure by mutating 28qpviv32 to 28aaaaa32 had no effect either on symptom phenotyp ... | 2011 | 21864876 |
| Form, symmetry and packing of biomacromolecules. IV. Filled capsids of cowpea, tobacco, MS2 and pariacoto RNA viruses. | Four icosahedral RNA viruses are considered: the cowpea chlorotic mottle virus, the satellite tobacco mosaic virus, the pariacoto virus and the MS2 bacteriophage. The validity of the phenomenological rules derived in previous publications (crystallographic scaling, indexed forms enclosing axial-symmetric clusters, packing lattices of viral crystals) is confirmed and shown to apply equally well to the coat proteins as to the (ordered) RNA chains. | 2011 | 22011467 |
| crystalline cowpea chlorotic mottle virus. | | 2015 | 4689956 |
| a method for the purification of large quantities of biologically active ribonucleic acid components from cowpea chlorotic mottle virus, a multicomponent plant virus. | cowpea chlorotic mottle virus rna has been prepared in comparatively high yield (at least 50%) by a modified phenol extraction method. the preparation, which has high biological activity, has been resolved into four components by zonal centrifugation on a 15-40% (w/v) sucrose density gradient. the components obtained have been tested for biological activity against whole plants and plant protoplasts. each of the two largest components rna 1 and rna 2 was by itself infective (50-90% of the specif ... | 2003 | 141815 |
| crystalline cowpea chlorotic mottle virus. | | 1998 | 21302 |
| feasibility of cowpea chlorotic mottle virus-like particles as scaffold for epitope presentations. | within the last decade virus-like particles (vlps) have increasingly received attention from scientists for their use as a carrier of (peptide) molecules or as scaffold to present epitopes for use in subunit vaccines. to test the feasibility of cowpea chlorotic mottle virus (ccmv) particles as a scaffold for epitope presentation and identify sites for epitope fusion or insertion that would not interfere with virus-like-particle formation, chimeric ccmv coat protein (cp) gene constructs were engi ... | 2015 | 26311254 |
| self-assembly of viral capsid protein and rna molecules of different sizes: requirement for a specific high protein/rna mass ratio. | virus-like particles can be formed by self-assembly of capsid protein (cp) with rna molecules of increasing length. if the protein "insisted" on a single radius of curvature, the capsids would be identical in size, independent of rna length. however, there would be a limit to length of the rna, and one would not expect rna much shorter than native viral rna to be packaged unless multiple copies were packaged. on the other hand, if the protein did not favor predetermined capsid size, one would ex ... | 2011 | 22205731 |
| coupling peptide antigens to virus-like particles or to protein carriers influences the th1/th2 polarity of the resulting immune response. | we have conjugated the s9 peptide, a mimic of the group b streptococcal type iii capsular polysaccharide, to different carriers in an effort to elicit an optimal immune response. as carriers, we utilized the soluble protein keyhole limpet hemocyanin and virus-like particles (vlps) from two plant viruses, cowpea chlorotic mottle virus and cowpea mosaic virus. we have found that coupling the peptide to the soluble protein elicits a th2 immune response, as evidenced by the production of the peptide ... | 2016 | 27164150 |
| open reading frame in the minus strand of two plus type rna viruses. | : inspection of the nucleotide sequences of the rnas complementary to the coat protein mrnas from two plant viruses with a tripartite genome: alfalfa mosaic virus and brome mosaic virus, showed the presence of open reading frames for 138 and 118 amino acids, respectively. a third virus (cowpea chlorotic mottle virus) from the same family (1) does not show this phenomenon. this suggests that if a protein is coded for by the open reading frames it may be not essential for virus multiplication. alt ... | 1982 | 24317896 |
| examining the heterogeneous genome content of multipartite viruses bmv and ccmv by native mass spectrometry. | since the concept was first introduced by brian chait and co-workers in 1991, mass spectrometry of proteins and protein complexes under non-denaturing conditions (native ms) has strongly developed, through parallel advances in instrumentation, sample preparation, and data analysis tools. however, the success rate of native ms analysis, particularly in heterogeneous mega-dalton (mda) protein complexes, still strongly depends on careful instrument modification. here, we further explore these bound ... | 2016 | 26926442 |
| a novel set of polyvalent primers that detect members of the genera bromovirus and cucumovirus. | rapid detection and diagnosis of plant virus infection is one of the most important steps in preventing damages caused by viral diseases. bromoviruses and cucumoviruses belong to the family bromoviridae, which is one of the most important families of plant viruses, and infect a broad range of host plants including various economically important crops. in this study, an rt-pcr assay was developed for the universal detection of bromoviruses and cucumoviruses using a set of primers designed to targ ... | 2014 | 24717165 |
| electrophoretic mobilities of a viral capsid, its capsid protein, and their relation to viral assembly. | the self-assembly of many viral capsids is dominated by protein-protein electrostatic interactions. to have a better understanding of this process, it is important to know how the protein and the capsid surface charges vary as a function of the ph and ionic strength. in this work, using phase analysis light scattering, we measured the electrophoretic mobility (em) of the cowpea chlorotic mottle virus (ccmv), its capsid protein (cp), and a cleaved cp that lacks its basic terminus, as a function o ... | 2014 | 24467401 |
| analysis of the solvent accessibility of cysteine residues on maize rayado fino virus virus-like particles produced in nicotiana benthamiana plants and cross-linking of peptides to vlps. | mimicking and exploiting virus properties and physicochemical and physical characteristics holds promise to provide solutions to some of the world's most pressing challenges. the sheer range and types of viruses coupled with their intriguing properties potentially give endless opportunities for applications in virus-based technologies. viruses have the ability to self- assemble into particles with discrete shape and size, specificity of symmetry, polyvalence, and stable properties under a wide r ... | 2013 | 23439009 |
| in vitro quantification of the relative packaging efficiencies of single-stranded rna molecules by viral capsid protein. | while most t=3 single-stranded rna (ssrna) viruses package in vivo about 3,000 nucleotides (nt), in vitro experiments have demonstrated that a broad range of rna lengths can be packaged. under the right solution conditions, for example, cowpea chlorotic mottle virus (ccmv) capsid protein (cp) has been shown to package rna molecules whose lengths range from 100 to 10,000 nt. furthermore, in each case it can package the rna completely, as long as the mass ratio of cp to nucleic acid in the assembl ... | 2012 | 22951822 |
| interstrain pseudorecombinants of cowpea chlorotic mottle virus: effects on systemic spread and symptom formation in soybean and cowpea. | full-length complementary dna (cdna) copies of genomic rna1, rna2, and rna3 segments of cowpea chlorotic mottle virus (ccmv) strains d, n, and s were synthesized using polymerase chain reaction and were cloned downstream of a t7 rna polymerase promoter. mixtures of the homologous in vitro-transcribed rnas produced typical ccmv symptoms when inoculated on soybean (cv. bragg) and cowpea (cv. california blackeye) plants. using either gel-purified or in vitro-transcribed ccmv rna components, the pse ... | 2006 | 8118057 |
| highly efficient strategy for the heterologous expression and purification of soluble cowpea chlorotic mottle virus capsid protein and in vitro ph-dependent assembly of virus-like particles. | obtaining pure and soluble viral capsid proteins (cps) has been a major challenge in the fields of science and technology in recent decades. in many cases, the cps can self-assemble in the absence of a viral genome, resulting in non-infectious, empty virus-like particles (vlps) which can be safely handled. the use of vlps has found great potential in biotechnology and health purposes. in addition, vlps are a good model system to study protein-protein interactions at the molecular level. in this ... | 2015 | 26342905 |
| to build a virus on a nucleic acid substrate. | many viruses package their genomes concomitant with assembly. here, we show that this reaction can be described by three coefficients: association of capsid protein (cp) to nucleic acid (na), kna; cp-cp interaction, ω; and α, proportional to the work required to package na. the value of α can vary as na is packaged. a phase diagram of average lnα versus lnω identifies conditions where assembly is likely to fail or succeed. na morphology can favor (lnα > 0) or impede (lnα < 0) assembly. as lnω be ... | 2013 | 23561536 |
| surveying capsid assembly pathways through simulation-based data fitting. | virus capsid assembly has attracted considerable interest from the biophysical modeling community as a model system for complicated self-assembly processes. simulation methods have proven valuable for characterizing the space of possible kinetics and mechanisms of capsid assembly, but they have so far been able to say little about the assembly kinetics or pathways of any specific virus. it is not possible to directly measure the detailed interaction rates needed to parameterize a model, and ther ... | 2012 | 23062347 |
| the mechanism of infection of plant protoplasts by viruses. | the process of virus infection of protoplasts isolated from tobacco leaves has been examined by means of electron microscopy. immediately after inoculation, virus particles appear at two types of site: trapped in complex surface lesions of the plasmalemma, or in peripheral cytoplasmic vesicles. the complex lesions are only visible after treatment of the protoplasts with inocula containing poly-l-ornithine. with infection by tobacco mosaic virus and cowpea chlorotic mottle virus, which require po ... | 1973 | 24468812 |
| physical principles in the self-assembly of a simple spherical virus. | viruses are unique among living organisms insofar as they can be reconstituted "from scratch", that is, synthesized from purified components. in the simplest cases, their "parts list" numbers only two: a single molecule of nucleic acid and many (but a very special number, i.e., multiples of 60) copies of a single protein. indeed, the smallest viral genomes include essentially only two genes, on the order of a thousand times fewer than the next-simplest organisms like bacteria and yeast. for thes ... | 2016 | 26653769 |