| observations and experiments on the use of an avirulent mutant strain of tobacco mosaic virus as a means of controlling tomato mosaic. | | 1975 | 1190569 |
| retention and dissociation of tobacco mosaic virus by tobacco protoplasts. | | 1975 | 1114698 |
| proceedings: enzymatic acylation of histidine to tobacco mosaic virus rna. | | 1975 | 1205798 |
| [effect of the method of tissue culture and the way of its inoculation as applied to the accumulation of potato virus x and tobacco mosaic virus]. | | 1975 | 1207517 |
| protein synthesis in tobacco protoplasts infected with tobacco mosaic virus. | | 1975 | 1114703 |
| the effect of cations on the alkaline dissociation of tobacco mosaic virus. | | 1975 | 1114714 |
| protein composition of unusual tobacco mosaic virus strains. | amino acid analyses have been made of the proteins of single-lesion isolates of five strains of tobacco mosaic virus (tmv) differentiated by lycopersicon hosts. these hosts differed in their genetical control of resistance to tmv, and the virus strains had therefore survived specific selection pressures. two of the five strains differed in their amino acid composition from type tmv and from all other tomato strains of tmv previously examined. symptoms induced by the five strains in four tomato l ... | 1975 | 1115413 |
| comparison between the 3'oh end rna sequence of two strains of tobacco mosaic virus (tmv) which may be aminoacylated. | | 1975 | 1227955 |
| the uncoating of native and reconstituted tmv by dimethylsulphoxide: the polarity of stripping. | the effect of increasing concentrations of dimethylsulphoxide (dmso) on the stability of native and reconstituted tobacco mosaic virus (tmv) has been investigated by means of electron microscopy and infectivity assay. the removal of protein subunits from tmv by dmso was found to be a stepwise process. subunits are first removed from the 3'oh end of the rod but at about 72% dmso the site at which uncoating occurs shifts to the 5' end. studies with reconstituted and partially reconstituted tmv con ... | 1975 | 1120937 |
| sodium dodecyl sulphate-polyacrylamide-gel electrophoretic detection of two high molecular weight proteins associated with tobacco mosaic virus infection in tobacco. | | 1976 | 1246828 |
| stable dimers of the coat protein of a strain of tobacco mosaic virus. | | 1976 | 1246829 |
| the amino acid sequence of the cowpea strain of tobacco mosaic virus protein. | the amino acid sequence of the coat protein of the cowpea strain of tobacco mosaic virus (cowpea virus) has been determined. the tryptic peptide overlaps were obtained by digesting the protein with chymotrypsin and separating and analysing the lysine-and arginine-containing chymotryptic peptides. the primary structure of cowpea virus protein has been found to differ markedly from that of any other known strain of tobacco mosaic virus, and contains 3 amino acid residues more and 96 amino acid cha ... | 1975 | 1138919 |
| the polarity of stripping of coat protein subunits from the rna in tobacco mosaic virus under alkaline conditions. | | 1976 | 1248634 |
| quantity of microinjected tobacco mosaic virus required for infection of single cultured tobacco cells. | | 1975 | 1129953 |
| the structure of the protein disk of tobacco mosaic virus to 5a resolution. | an electron density map of the tmv disk at 5a resolution has been obtained using isomorphous replacement and non-crystallographic symmetry. the polypeptide chain can be traced with little ambiguity. the axial contacts between protein subunits are unlike those in the virus, the disk being a more open structure apparently designed for rapid interaction with the rna. | 1976 | 1250335 |
| the role of long range forces in ordered arrays of tobacco mosaic virus. | we examine the role of electrostatic repulsion and van der waals' attraction in determining interviral spacings in 'equilibrium' gels of tobacco mosaic virus. the observed spacings are inconsistent with a force-balance model. experimental probes of the role of forces are suggested. | 1976 | 1250412 |
| in vitro hemolysis of autologous erythrocytes caused by immune murine spleen cells and spherules of the fungus coccidioides immitis. | this communication describes an in vitro system wherein mouse erythrocytes are lysed in the presence of spherules of the fungus coccidioides immitis and spleen cells from syngeneic mice immunized with a variety of antigens. the antigens include: tobacco mosaic virus in complete freund's adjuvant (cfa), cfa alone, separate components of cfa, sheep erythrocytes, and allogeneic tumor. spleen cells from mice sublethally infected with c. immitis are also capable of participating in this response. the ... | 1976 | 1254972 |
| selection of temperature-sensitive mutants of tobacco mosaic virus by lesion morphology. | | 1975 | 1129954 |
| the relationship of ethylene to formation of tobacco mosaic virus lesions in hypersensitive responding tobacco leaves with and without induced resistance. | | 1975 | 1136134 |
| immunochemical studies of tobacco mosaic virus--i: refutation of the alleged homogeneous binding of purified antibody fragments. | | 1975 | 1218890 |
| fate of tobacco mosaic virus after entering the host cell. ii. electron microscopy of virus particles recovered from inoculated leaves. | | 1975 | 1223339 |
| assembly of tobacco mosaic virus in vitro. improved model for the elongation process by protein subunits. | the in vitro assembly reaction of tobacco mosaic virus (tmv), especially the elongation process of partially reconstituted rna (prr) by protein subunits, was observed by electron microscopy. after addition of tmv-protein subunits, the prr appeared as rods with a clump at one end, believed to be a complex between added protein subunits and the rna tail protruding from prr. the subunits entrapped on the rna tails in the forms of clumps were progressively incorporated into the growing rods on incub ... | 1975 | 1225901 |
| partial characterization of virus-like particles in chloroplasts of plants infected with the u5 strain of tmv. | | 1975 | 1136145 |
| the conformational specificity of viral epitopes. | four types of antigenic sites found in viruses are discussed: cryptotopes, neotopes, metatopes and neutralization epitopes. the role played by conformation on the specificity of viral epitopes is illustrated in the case of tobacco mosaic virus and influenza virus. it appears that mechanisms reminiscent of induced fit contribute to the recognition of viral epitopes by antibodies. | 1992 | 1282485 |
| guanidine inhibits tobacco mosaic virus rna synthesis at two stages. | guanidine (gd) inhibited tobacco mosaic virus (tmv) rna synthesis at two different steps, depending on the concentration of gd used. the time-course of inhibition by 40 mm gd coincided with the time-course of rna synthesis. however, 10 mm gd inhibited an earlier step that occurred prior to viral rna synthesis. | 1975 | 1235830 |
| thermally induced conformational changes of tobacco mosaic virus and their protein assemblies. | the measurement of the fluorescence intensity of tryptophan residues showed that a reversible transition in the local structure took place between 20 degrees c and 30c in intact virus particles and reconstituted protein assemblies of the ordinary strain and the tomato strain of tobacco mosaic virus. during this transition the overall polymer structure was maintained. in the case of the bean strain of tobacco mosaic virus, however, the fluorescence intensity did not show any transition in the sam ... | 1975 | 1125268 |
| replication of tobacco mosaic virus rna in tobacco mesophyll protoplasts inoculated in vitro. | | 1975 | 1129946 |
| yucca leaf protein (ylp) stops the protein synthesis in hsv-infected cells and inhibits virus replication. | yucca leaf protein (ylp), an inhibitor of tobacco mosaic virus isolated from the leaves of yucca recurvifolia salisb., exhibited potent activity against herpes simplex virus type 1 (hsv-1) with no cytotoxicity below 300 micrograms/ml. the inhibitory dose was varied with the time of addition; 50% effective concentrations (ed50) of ylp were 3, 19 and 95 micrograms/ml when ylp exposure was begun 3 h before virus infection, 0 h and 3 h after infection, respectively. this protein also inhibited the m ... | 1992 | 1322646 |
| a prediction of the structure of tobacco-mosaic-virus protein. | the location of amino acid residues within the tobacco mosaic virus protein subunit is discussed. sequence data, x-ray crystallographic measurements, and the availability of specific residues for enzymic, immunological or chemical reaction are amongst the information used to trace roughly how the tobacco mosaic virus polypeptide chain winds in and out from the virus axis. published rules for predicting secondary structure are then applied to obtain a diagram of the course of the polypeptide chai ... | 1975 | 1140193 |
| co2 effects on local-lesion production by tobacco mosaic virus and turnip mosaic virus. | | 1975 | 1129950 |
| establishment of hybridoma cell line secreting specific monoclonal antibodies against turnip mosaic virus and analysis of properties of the mcab. | monoclonal antibodies (mcab) of hybridomas derived from the fusing of the mouse splenocytes immunized by tumv with balb/c mouse myeloma cells (sp2/0-ag14). five kinds of hybridoma cell line were produced by indirect-elisa screening and cloning three times with limiting dilution. four kinds of hybridoma produced antibodies respectively reactive to tumv c1, c3, c4 and c5. one kind was reactive to all five strains of tumv. in indirect-elisa and sandwich-elisa tests, tumv specific monoclonal antibod ... | 1992 | 1343828 |
| construction of a yeast artificial chromosome library of tomato and identification of cloned segments linked to two disease resistance loci. | we have constructed a yeast artificial chromosome (yac) library of tomato for chromosome walking that contains the equivalent of three haploid genomes (22,000 clones). the source of high molecular weight dna was leaf protoplasts from the tomato cultivars vfnt cherry and rio grande-ptor, which together contain loci encoding resistance to six pathogens of tomato. approximately 11,000 yacs have been screened with rflp markers that cosegregate with tm-2a and pto - loci conferring resistance to tobac ... | 1992 | 1351245 |
| the effect of an egyptian isolate of streptomyces afghanensis on some plant viruses. | an egyptian isolate of streptomyces afghanensis was examined for the production of antiviral metabolites. concentrated broth exudates of this microorganism were tested against tobacco mosaic virus (tmv), tomato mosaic virus (tomv) and potato virus x (pvx) infecting nicotiana tabacum l. cv. white burley. both concentrated metabolites and their acetone extract inhibited local lesion development of the tested viruses. in all cases, maximum antiviral effect was observed 2 hr after infection. the ult ... | 1992 | 1364025 |
| synthesis of tobacco mosaic virus in intact tobacco leaves systemically inoculated by differential temperature treatment. | | 1975 | 1129951 |
| interaction between viruses and monoclonal antibodies studied by surface plasmon resonance. | an automated biosensor system designed for measuring molecular interactions in real time and without any labelling of the reactants has been used to study the interaction of two animal viruses (vaccinia virus and poliovirus) and two plant viruses (cowpea mosaic virus and tobacco mosaic virus) with monoclonal antibodies. using monoclonal antibodies specific for different conformational states of viral protein, it was found that the virus particles retained their conformational integrity when immo ... | 1992 | 1372280 |
| the inhibitory action of mineral oil on the number of local lesions on nicotiana glutinosa l. leaves inoculated with tobacco mosaic virus. | | 1975 | 1129952 |
| sequence of a specifically encapsidated rna fragment originating from the tobacco-mosaic-virus coat-protein cistron. | when 25-s tobacco mosaic virus (tmv) protein aggregate and tmv rna, which has been partially digested by t1 rnase, are mixed under conditions suitable for reconstitution, only a few rna fragments are encapsidated. these fragments were isolated and purified by polyacrylamide gel electrophoresis. the sequence of the three main fragments, the longest of which (fragment 1) was estimated to contain 103 nucleotides, has been determined. the two smaller fragments are portions of the longer chain produc ... | 1975 | 1149744 |
| observations concerning the sequence of two additional specifically encapsidated rna fragments originating from the tobacco-mosaic-virus coat-protein cistron. | the incubation of 25-s tobacco mosaic virus (tmv) protein with a mixture of rna fragments produced by partial t1 rnase digestion of tmv rna results in the encapsidation of only a few species of rna. in addition to the most predominant species, fragment 1, whose sequence has been described in the prededing paper, two other species, fragment 41 and fragment 21 are coated by the protein. these two rna fragments were purified by polyacrylamide gel electrophoresis and subjected to total digestion wit ... | 1975 | 1149745 |
| efficiency of the 5'-terminal sequence (omega) of tobacco mosaic virus rna for the initiation of eukaryotic gene translation in escherichia coli. | recent studies have demonstrated that the 5' leader (omega sequence) of tobacco mosaic virus rna has a certain enhancing capacity for translation of mrna in both prokaryotes and eukaryotes. in order to estimate the efficiency of omega to initiate translation of mrna in escherichia coli, in comparison to the shine-dalgarno (s/d) sequence, we have inserted eight different eukaryotic genes into two types of e. coli expression vectors containing one constitutive promoter (p1) but different translati ... | 1992 | 1396694 |
| construction of a chimeric viral gene expressing plum pox virus coat protein. | the capsid-encoding gene of plum pox virus (ppv) was fused with the leader sequence of the coat protein mrna (cp) of tobacco mosaic virus by a novel mutagenesis technique which involves reverse transcription of minus-strand rna [synthesized by in vitro transcription of a double-stranded (ds) cdna clone], using an ad hoc synthetic oligodeoxynucleotide as primer. the resulting cdna was rendered ds and cloned into the plasmid, pbluescribe m13+. transcription of this chimeric construction produced r ... | 1992 | 1398133 |
| [determination of the effectiveness of rna cross-linking with protein induced by uv-radiation in potato x-virus particles]. | the uv-irradiation was found to induce formation of the rna-protein cross-links and intraviral rna chain breaks in the particles of flexuous potato virus x (pvx). using the technique developed previously for the rod-like tobacco mosaic virus (tmv), the quantum yields of rna-protein cross-links and intraviral rna polynucleotide chain breaks formation in the pvx were determined and found to be more or less close to those found for the intraviral tmv rna. | 1992 | 1406761 |
| inactivation of tobacco mosaic virus ribonucleic acid by near- and middle- ultraviolet light: sensitization by sulfanilamide and chlortetracycline. | | 1975 | 1156417 |
| scanning force microscopy and cryo-electron microscopy of tobacco mosaic virus as a test specimen. | in this study, tobacco mosaic virus (tmv) provides a resolution criterion for specimen preparation methods as well as for imaging parameters of the scanning force microscope (sfm). we present scanning force microscopic images of the virus embedded in 0.5% buffered phosphotungstic acid solution adsorbed on a freshly cleaved mica surface, and imaged under atmospheric conditions. individual tmv particles were clearly identified with a characteristic shape of long rods of about 300 nm long and 60-70 ... | 1992 | 1413254 |
| cis-acting elements for in trans complementation of replication-defective mutant of tobacco mosaic virus. | we have shown that virus-encoded replicase components of tobacco mosaic virus (tmv)(130k/180k proteins) could complement a replication-defective mutant (ldr28) for viral replication in trans [ogawa et al. virology 185, 580-584 (1991)]. using this trans-complementation system, we investigated the dispensability of regions of the 130k/180k protein genes as cis-acting elements for viral replication. a series of replication-defective mutants (ldrs) which had various deletions in the 130k/180k coding ... | 1992 | 1413517 |
| infinite-dilution viscoelastic properties of tobacco mosaic virus. | | 1975 | 1174670 |
| intracellular distribution of the 126k/183k and capsid proteins in cells infected by some tobamoviruses. | leaves of plants infected by tobacco mosaic virus (tmv) strain u1, tmv strain m, tomato mosaic virus strain dahlemense and tobacco mild green mosaic virus strain u2 were examined for the presence and intracellular distribution of their capsid and 126k/183k proteins by immunoblotting and immunogold electron microscopy. the bulk of the capsid protein was found in the virus bundles (crystals), although small amounts were found in the chloroplasts and nuclei of cells infected by some of these tobamo ... | 1992 | 1431815 |
| nucleotide sequence of cdna of the tobacco mosaic virus rna isolated in korea. | | 1992 | 1437566 |
| [plant rna virus--tmv replication]. | | 1992 | 1438840 |
| inhibition of multiplication of tobacco mosaic virus in protoplasts by antibiotics and its prevention by divalent metals. | at concentrations that inhibit bacterial growth, some antibiotics including gentamicin completely inhibited virus multiplication in protoplasts, and other antibiotics partially inhibited virus multiplication. the inhibition caused by each antibiotic was largely prevented by adding a divalent metal; mnc1(2) was more effective than cac1(2) and other salts of divalent metals when added at 10 mm to the incubation medium. when added immediately after infection, 1 mug/ml of gentamicin halved the final ... | 1975 | 1176964 |
| accumulation of the 126 kda protein of tobacco mosaic virus during systemic infection analysed by immunocytochemistry and elisa. | systemic infection of tobacco with tobacco mosaic virus (tmv) strain wu1, is accompanied by massive accumulation of the virus-coded non-structural 126 kda protein in x-bodies. the development of x-bodies and the time course of the increase in 126 kda protein in systemically infected leaves were analyzed by immunocytochemistry and elisa, respectively, using an antiserum raised against a fusion protein of beta-galactosidase and part of the 126 kda protein. the elisa assay developed enabled routine ... | 1992 | 1456890 |
| purification of filamentous plant viruses by thin layer centrifugation. | the construction of a modified thin layer ultracentrifuge rotor is described. this rotor was used in the purification of five filamentous plant viruses, viz. tmv, scmv, pvx, sgv and ymc. the purification and concentration of these viruses in their monomeric forms is hazardous when conventional "tube" rotors are used since they invariably result in dissociation and aggregation of the virus particles. using the thin layer rotor these infective agents may be concentrated in volumes of fluid equal t ... | 1975 | 1178651 |
| [proceedings: immunochemistry of tobacco mosaic virus (tmv). determination of association constants of fab fragments]. | | 1975 | 1180499 |
| a new multigene family inducible by tobacco mosaic virus or salicylic acid in tobacco. | a previously undescribed cdna family was isolated from tobacco challenged with tobacco mosaic virus (tmv). a cdna library was constructed with mrna from upper leaves of xanthi nc tobacco plants that had been inoculated with tmv on the lower leaves 11 days previously. the library was screened differentially with radiolabeled cdna synthesized with mrna from upper, uninoculated leaves of either tmv-inoculated or mock-inoculated tobacco plants. the new cdna family, designated sar8.2, had at least fi ... | 1992 | 1477404 |
| quantitation of molecular densities by cryo-electron microscopy. determination of the radial density distribution of tobacco mosaic virus. | we have determined the absolute mass and radial scattering density distribution of tobacco mosaic virus in the frozen-hydrated state by energy-filtered low-dose bright-field transmission electron microscopy. the absolute magnitude of electron scattering from tobacco mosaic virus in 150 nm of ice was within 3.0% of that predicted, with inelastic scattering accounting for approximately 80% of the scattering contrast. in order to test the accuracy of the radial reconstruction, a computer model of t ... | 1992 | 1507225 |
| synthesis of tobacco mosaic virus coat protein following migration of viral rna into isolated mouse liver mitochondria. | rna of tobacco mosaic virus is shown to be able to migrate into isolated mouse liver mitochondria, whence it can be reisolated intact. the migration of rna is accompanied by enhanced rate of protein synthesis, which is sensitive to chloramphenicol, but not to cycloheximide. evidence is presented showing that, among the products formed is the coat protein of tobacco mosaic virus. | 1975 | 1187342 |
| location of the cistron of the tobacco mosaic virus coat protein. | treatment of tobacco mosaic virus (tmv) rna with t1 rnase under mild conditions cuts the rna molecule into a large number of fragments, only a few of which may be specifically recognized by disks of tmv protein. it has been shown elsewhere that these specifically recognized rna fragments are a part of the coat protein cistron, the portion coding for amino acids 95 to 129 of the coat protein. it is reported that different size classes of partially uncoated virus particles were prepared by limited ... | 1975 | 1203319 |
| messenger rna for the coat protein of tobacco mosaic virus. | tmv rna is not an efficient template for translation of the viral coat protein, in spite of containing nucleotide sequences coding for the protein. efficient translation requires the prior synthesis within infected cells of a smaller rna carrying only a portion of the information encoded in the whole genome. | 1976 | 1264250 |
| a new helical aggregate of tobacco mosaic virus protein. | | 1976 | 1271465 |
| proceedings: interaction of tobacco mosaic virus strains in doubly infected tobacco protoplasts. | | 1976 | 1275399 |
| effects of terminal deletion mutations on function of the movement protein of tobacco mosaic virus. | a series of carboxy- and amino-terminal deletion mutations in the movement protein (mp) gene of tobacco mosaic virus (tmv) were ligated into a cloned tmv cdna deleted for the endogenous mp gene. rna transcripts were produced in vitro from clones carrying the various mutated mp genes. the effect of the deletion mutations on local and systemic movements of the infection was evaluated. deletion of 9 or 33 amino acids from the carboxy terminus of the movement protein did not effect cell-to-cell move ... | 1992 | 1546450 |
| proceedings: new species of rna formed during tobacco mosaic virus infection. | | 1976 | 1275403 |
| proceedings: the cowpea strain of tmv is a pseudo-multicomponent virus. | | 1976 | 1275404 |
| resistance to tobacco mosaic virus induced by the 54-kda gene sequence requires expression of the 54-kda protein. | tobacco plants transformed with the sequence encoding the 54-kda putative replicase protein of tobacco mosaic virus were resistant to systemic virus disease (d. b. golemboski, g. p. lomonossoff, and m. zaitlin, proc. natl. acad. sci. usa 87:6311-6315, 1990). resistance was due to a marked suppression of virus replication at the site of inoculation (j. p. carr and m. zaitlin, mol. plant-microbe interact. 4:579-585, 1991). although rna transcripts encoding the 54-kda protein were present in resist ... | 1992 | 1282044 |
| biophysical and biochemical properties of baculovirus-expressed camv p1 protein. | cauliflower mosaic virus (camv) gene i encodes a protein (p1) that has been implicated in the control of virus movement in infected plants. to assist in the characterization of the mechanism of action of p1, gene i has been expressed efficiently in spodoptera frugiperda (sf) cells using recombinant baculovirus. control of the expression of camv gene i by the polyhedrin late promoter in the baculovirus autographa californica nuclear polyhedrosis virus (acnpv) resulted in very high levels of p1 ac ... | 1992 | 1549910 |
| ascorbate peroxidase activity in resistant and susceptible plants of lycopersicon esculentum. | activity of redox-enzymes of aa system and of catalase was measured in two near-isogenic tomato lines, respectively resistant and susceptible to tobacco mosaic virus infection. afr reductase, dha reductase and catalase showed quite similar activities in both lines, whereas aa peroxidase activity in resistant plants was 75% higher than in susceptible ones, with km values about 4-fold lower. these data suggest that hydrogen peroxide scavenging operated by aa peroxidase could play an important role ... | 1992 | 1295516 |
| macromolecular crystal growth experiments on international microgravity laboratory--1. | macromolecular crystal growth experiments, using satellite tobacco mosaic virus (stmv) and canavalin from jack beans as samples, were conducted on a us space shuttle mission designated international microgravity laboratory--1 (iml-1), flown january 22-29, 1992. parallel experiments using identical samples were carried out in both a vapor diffusion-based device (pcg) and a liquid-liquid diffusion-based instrument (cryostat). the experiments in each device were run at 20-22 degrees c and at colder ... | 1992 | 1303744 |
| electric birefringence in concentrated solutions of tobacco mosaic virus. | | 1976 | 1247661 |
| the hexagonal lattice spacing of intracellular crystalline tobacco mosaic virus. | | 1976 | 1249852 |
| characterization of a putative calcium-binding site in tobacco mosaic virus. | lead has been used as a substitute for calcium binding to tobacco mosaic virus (tmv). the high atomic number of lead has allowed us to use difference maps from x-ray fiber diffraction data to characterize a calcium-binding site in the virus. the metal ligands are slightly different from those previously believed to bind calcium to tmv, although the binding site is very close to one previously described. two acetate groups are also bound to the lead atom. there is no significant backbone conforma ... | 1992 | 1603802 |
| codon context effect in virus translational readthrough. a study in vitro of the determinants of tmv and mo-mulv amber suppression. | to assess the role of codon context on the efficiency of eukaryotic suppression of termination codons, we have compared, in a rabbit cell-free translation system, the readthrough efficiency related to two synthetic transcripts differing by the codon context around an amber codon. the codon contexts are derived from tobacco mosaic virus (tmv) and moloney murine leukemia virus (mo-mulv) rnas. the mo-mulv-like codon context does not promote suppression. substituting tmv-derived triplets in the mo-m ... | 1992 | 1321731 |
| the 5' untranslated region from pea seedborne mosaic potyvirus rna as a translational enhancer in pea and tobacco protoplasts. | we have exploited the transient expression of foreign genes introduced into plant protoplasts to investigate the effect of the pea seedborne mosaic potyvirus (psbmv) 5' untranslated region (5'utr) on the level of gene expression in pea and tobacco protoplasts. the plant viral 5'utrs were found to increase translation significantly in comparison to a plasmid containing no 5'utr of viral origin. the enhancement effect of the 5'utrs of psbmv and tobacco etch potyvirus (tev) was found to be similar ... | 1992 | 1607015 |
| quantitative energy-filtered electron microscopy of biological molecules in ice. | the theoretical and experimental bases for quantitative electron microscopy of frozen-hydrated specimens are described, with special considerations of energy filtration to improve the images. the elastic and inelastic scattering from molecules in vacuum and in ice are calculated, and simple methods to approximate scattering are introduced. multiple scattering calculations are used to describe the scattering from vitreous ice and to predict the characteristics of images of frozen-hydrated molecul ... | 1992 | 1336234 |
| nucleotide sequence of carnation ringspot dianthovirus rna-2. | rna-2 of carnation ringspot virus (crsv), the type member of the dianthovirus group, has been cdna cloned and sequenced. crsv rna-2 is 1394 nucleotides in length and contains a single open reading frame encoding a 304 amino acid polypeptide of 33.8k. amino acid sequence alignment of this polypeptide with the cell-to-cell movement proteins encoded by rna-2 of red clover necrotic mosaic virus (rcnmv) australian (aus) and czechoslovakian (tpm-34) isolates indicates 59.6% and 55.7% sequence identity ... | 1992 | 1339467 |
| alternative staining methods for lowicryl sections. | a number of stains and stain combinations have been identified that, when used with the hydrophilic resin lowicryl k11m, produce marked improvements over aqueous uranyl and lead salts (ua-pb) in terms of low granularity, specificity, and range of components contrasted. three test specimens, tobacco mosaic virus (tmv), starfish sperm, and cultured mouse fibroblasts, were used to evaluate stain characteristics. ua-pb showed a preference for nuclei acids, which were stained specifically by osmium a ... | 1992 | 1370308 |
| visualization and characterization of tobacco mosaic virus movement protein binding to single-stranded nucleic acids. | cell-to-cell spread of tobacco mosaic virus (tmv) is presumed to occur through plant intercellular connections, the plasmodesmata. viral movement is an active process mediated by a specific virus-encoded p30 protein. p30 has at least two functions, to cooperatively bind single-stranded nucleic acids and to increase plasmodesmatal permeability. here, we visualized p30 complexes with single-stranded dna and rna. these complexes are long, unfolded, and very thin (1.5 to 2.0 nm in diameter). unlike ... | 1992 | 1379865 |
| systemic expression of a bacterial gene by a tobacco mosaic virus-based vector. | tobacco mosaic virus (tmv) produces large quantities of rna and protein on infection of plant cells. this and other features, attributable to its autonomous replication, make tmv an attractive candidate for expression of foreign sequences in plants. however, previous attempts to construct expression vectors based on plant rna viruses, such as tmv, have been unsuccessful in obtaining systemic and stable movement of foreign genes to uninoculated leaves in whole plants. a hybrid viral rna (tb2) was ... | 1991 | 1651497 |
| mapping of viral epitopes with conformationally specific monoclonal antibodies using biosensor technology. | an automated biosensor system (biacore) designed for measuring molecular interactions in real time and without labelling any of the reactants was used for mapping the epitopes of tobacco mosaic virus protein using conformationally specific monoclonal antibodies (mabs). some of the mabs used as capturing antibody on the sensor chip allowed a conformational change to occur in the viral protein. as a result, mabs specific for the quaternary structure of polymerized viral protein were able to bind t ... | 1992 | 1381370 |
| structure of viral b-cell epitopes. | four categories of viral epitopes can be distinguished that have been designated cryptotopes, neotopes, metatopes and neutralization epitopes. specific examples of each epitope type are presented and the methods used for locating their positions in viral proteins are described. the epitopes of four well-characterized viruses, namely poliovirus, foot-and-mouth disease virus, influenza virus and tobacco mosaic virus are briefly described. | 1990 | 1714092 |
| alleged common antigenic determinant of tobacco mosaic virus coat protein and the host protein ribulose-1,5-bisphosphate carboxylase is an artifact of indirect elisa and western blotting. | we have reported the detection of an antigenic determinant shared by the tobacco mosaic virus coat protein and the large subunit of ribulose-1,5-bisphosphate carboxylase, a host protein (r.g. dietzgen and m. zaitlin virology 155, 262-266, 1986). this conclusion was questioned by d. zimmermann and m.h.v. van regenmortel (arch. virol. 106, 15-22, 1989). thus we have reinvestigated this unexpected serological cross-reaction in western immunoblotting and indirect elisa. we found that when skimmed mi ... | 1991 | 1714664 |
| secondary plasmodesmata are specific sites of localization of the tobacco mosaic virus movement protein in transgenic tobacco plants. | expression of the tobacco mosaic virus 30-kd movement protein (tmv mp) gene in tobacco plants increases the plasmodesmatal size exclusion limit (sel) 10-fold between mesophyll cells in mature leaves. in the present study, we examined the structure of plasmodesmata as a function of leaf development. in young leaves of 30-kd tmv mp transgenic (line 274) and vector control (line 306) plants, almost all plasmodesmata were primary in nature. in both plant lines, secondary plasmodesmata were formed, i ... | 1992 | 1392601 |
| identification of the motifs within the tobacco mosaic virus 5'-leader responsible for enhancing translation. | the leader (called omega) of tobacco mosaic virus rna enhances translation in both eukaryotes and prokaryotes. although little secondary structure is predicted to exist within omega, the primary sequence of the 68 base leader is highly organized. three copies of an eight base direct repeat and a (caa)n region represent the two motifs found in the leaders of many tmv strains, and together these comprise 72% of omega. in previous deletion studies, no mutants exhibited loss-of-function, suggesting ... | 1992 | 1408765 |
| analysis of cis-regulatory elements involved in induction of a tobacco pr-5 gene by virus infection. | cis-regulatory elements involved in tobacco mosaic virus (tmv)-inducible expression were identified in a tobacco pr-5 gene, encoding an acidic thaumatin-like protein. by fusing upstream sequences of the pr-5 gene to the gus reporter gene and analysing transgenic plants containing these fusions for local and systemic induction of gus activity by tmv, it was found that sequences between -1364 and -718 are involved in tmv induction of pr-5 gene expression. | 1992 | 1731969 |
| in vivo phosphorylation of the 30-kda protein of tobacco mosaic virus. | the 30-kda protein of tobacco mosaic virus, which is involved in cell-to-cell movement function, is phosphorylated in tobacco protoplasts. to investigate which portion of the protein is phosphorylated we inoculated several truncated 30-kda protein mutants into protoplasts and determined whether or not those truncated proteins are phosphorylated. the results showed that amino acid residues 234-261 of the 30-kda protein are required for this phosphorylation. | 1992 | 1426287 |
| pathogenesis-related protein 4 is structurally homologous to the carboxy-terminal domains of hevein, win-1 and win-2. | the extracellular, acidic pathogenesis-related protein, pr-4, was purified to homogeneity from leaves of nicotiana tabacum infected with tobacco mosaic virus (tmv) and characterized by partial amino acid sequencing. complementary dna clones encoding pr-4 were isolated using an oligonucleotide probe based on the sequence of one of the peptides. the deduced pr-4 protein sequence was found to be related to a family of proteins including hevein and win-1, which have an amino-terminal lectin domain a ... | 1991 | 1745223 |
| isolation of mutants of arabidopsis thaliana in which accumulation of tobacco mosaic virus coat protein is reduced to low levels. | we have found that arabidopsis thaliana is susceptible to infection with a crucifer strain of tobacco mosaic virus (tmv-cg); the coat protein of tmv-cg accumulated to a high level in uninoculated rosette leaves several days after inoculation. as a first step in the search for host-coded factors that are involved in virus multiplication, we isolated mutants of a. thaliana in which the accumulation of tmv-cg coat protein was reduced to low levels. of 6000 m2 plants descended from ethyl methanesulf ... | 1991 | 1745239 |
| translational efficiency and competitive ability of mrnas with 5'-untranslated alpha beta-leader of potato virus x rna. | the 5'-untranslated leader sequence of potato virus x (pvx) rna (63 nucleotides apart from cap-structure) consists of two sub-sequences referred to as alpha-sequence (41 nucleotides with no g) and beta-sequence (42 nucleotides upstream from the first aug). computer-based folding predictions suggest that the 5'-proximal region of alpha beta-leader is unstructured. the second structural feature of alpha beta-leader is the presence of the sequences apparently complementary to the 3'-terminal region ... | 1991 | 1764504 |
| structure of the u2 strain of tobacco mosaic virus refined at 3.5 a resolution using x-ray fiber diffraction. | the structure of the u2 strain of tobacco mosaic virus (tmv) has been determined by fiber diffraction methods at 3.5 a resolution, and refined by a combination of restrained least-squares and molecular dynamics methods to an r-factor of 0.096. the structure is extremely similar to that of the common strain of tmv, with the largest differences being in the protein loop that makes up the inner surface of the virus, and in the c-terminal region on the outer surface. differences in the inner loop ca ... | 1992 | 1453461 |
| tobacco and tomato pr proteins homologous to win and pro-hevein lack the "hevein" domain. | clones corresponding to tobacco pathogenesis-related (pr) proteins pr-4 and tomato pr protein p2 were isolated from phage cdna libraries of tobacco infected with tobacco mosaic virus and tomato infected with cladosporium fulvum, respectively. the probe used in these screenings was a polymerase chain reaction product, synthesized on phage dna from the tobacco cdna library, using a synthetic oligonucleotide primer whose sequence corresponded to the partial amino acid sequence available for p2. the ... | 1991 | 1804403 |
| pseudouridine in the anticodon g psi a of plant cytoplasmic trna(tyr) is required for uag and uaa suppression in the tmv-specific context. | we have previously isolated and sequenced nicotiana cytoplasmic trna(tyr) with g psi a anticodon which promotes readthrough over the leaky uag termination codon at the end of the 126 k cistron of tobacco mosaic virus rna and we have demonstrated that trna(tyr) with q psi a anticodon is no uag suppressor. here we show that the nucleotide in the middle of the anticodon (i.e., psi 35) also contributes to the suppressor efficiency displayed by cytoplasmic trna(tyr). a trna(tyr) with gua anticodon wa ... | 1992 | 1461724 |
| the nucleotide sequence of rna-1 of raspberry bushy dwarf virus. | raspberry bushy dwarf virus (rbdv) has isometric, 33 nm diameter particles and a bipartite rna genome. sequencing of the larger component (rna-1) showed that it consists of 5449 nucleotides and contains one large open reading frame encoding a putative translation product with a calculated m(r) of 190,000. comparisons of this polypeptide with non-structural proteins of other plant viruses revealed significant homologies with those of alfalfa mosaic virus (almv), brome mosaic virus (bmv), cucumber ... | 1992 | 1469359 |
| structure of tobraviral particles: a model suggested from sequence conservation in tobraviral and tobamoviral coat proteins. | comparisons of the coat protein sequences of four tobraviruses with those of seven tobamoviruses indicate that these proteins share a common evolutionary origin. numerous amino acids for which specific functions have been identified in the molecular structure of the tobacco mosaic virus vulgare protein have identical or closely similar counterparts among the tobraviral proteins. these include those with roles in the hydrophobic core of the protein, those that contribute to the rna binding site a ... | 1992 | 1522581 |
| production of the tobacco mosaic virus (tmv) transport protein in transgenic plants is essential but insufficient for complementing foreign virus transport: a need for the full-length tmv genome or some other tmv-encoded product. | we have reported previously that tobamoviruses enable the transport of red clover mottle comovirus (rcmv) in tobacco plants normally resistant to rcmv. here we show that rcmv transport does not take place in transgenic tobacco plants (line to-4) producing the 30k transport protein of tobacco mosaic virus (tmv), whereas the transport of the tmv ls1 mutant, the cell-to-cell movement of which is temperature sensitive, is complemented in these plants. however, rcmv transport is observed when these t ... | 1992 | 1538197 |
| the complete nucleotide sequence of cucumber green mottle mosaic virus (sh strain) genomic rna. | the complete nucleotide sequence of the genomic rna of cucumber green mottle mosaic virus watermelon strain sh (cgmmv-sh) was determined using cloned cdna. this sequence is 6421 nucleotides long containing at least four open reading frames, which correspond to 186k, 129k, 29k and 17.3k proteins. the 17.3k protein is the coat protein. sequence analysis shows that cgmmv-sh is very closely related to another watermelon strain. cgmmv-w, although three amino acid substitutions in the 29k protein were ... | 1991 | 1856687 |
| reinvestigation of intracellular localization of the 30k protein in tobacco protoplasts infected with tobacco mosaic virus rna. | it has been shown that the 30k protein of tobacco mosaic virus (tmv) is responsible for the cell-to-cell movement function of the virus. it is still obscure how the protein is involved in this function at the molecular level. we formerly found that the 30k protein is localized to the plasmodesmata of tmv-infected plants. we also reported that the 30k protein was detected in a nuclei-rich fraction of tmv-infected protoplasts after biochemical fractionation. to clarify the inconsistency, the 30k p ... | 1992 | 1546469 |
| normal modes of symmetric protein assemblies. application to the tobacco mosaic virus protein disk. | we use group theoretical methods to study the molecular dynamics of symmetric protein multimers in the harmonic or quasiharmonic approximation. the method explicitly includes the long-range correlations between protein subunits. it can thus address collective dynamic effects, such as cooperativity between subunits. the n lowest-frequency normal modes of each individual subunit are combined into symmetry coordinates for the entire multimer. the hessian of the potential energy is thereby reduced t ... | 1992 | 1547329 |
| localization, conjugation, and function of salicylic acid in tobacco during the hypersensitive reaction to tobacco mosaic virus. | salicylic acid (sa) is hypothesized to be a natural signal that triggers the systemic induction of pathogenesis-related proteins and disease resistance in tobacco. when xanthi-nc (nn genotype) tobacco was inoculated with tobacco mosaic virus (tmv) there was an increase in endogenous sa in both inoculated and virus-free leaves. the highest levels of sa were detected in and around necrotic lesions that formed in response to tmv. chemical and enzymatic hydrolysis of extracts from tmv-inoculated lea ... | 1992 | 1549613 |
| post-transcriptional regulation in higher eukaryotes: the role of the reporter gene in controlling expression. | we have investigated whether reporter genes influence cytoplasmic regulation of gene expression in tobacco and chinese hamster ovary (cho) cells. two genes, uida encoding beta-glucuronidase (gus) from escherichia coli and luc, encoding firefly luciferase (luc), were used to analyze the ability of a cap, polyadenylated tail, and the 5'- and 3'-untranslated regions (utr) from tobacco mosaic virus (tmv) to regulate expression. the regulation associated with the 5' cap structure and the tmv 5'-utr, ... | 1991 | 1886610 |
| direct visualization of the structure of the "20 s" aggregate of coat protein of tobacco mosaic virus. the "disk" is the major structure at ph 7.0 and the proto-helix at lower ph. | we have employed the rapid-freeze technique to prepare specimens for electron microscopy of a coat protein solution of tobacco mosaic virus at equilibrium at ph 7.0 and 6.8, ionic strength 0.1 m and 20 degrees c. the former are the conditions for the most rapid assembly of the virus from its isolated protein and rna. at both ph values, the equilibrium mixture contains approximately 80% of a "20 s" aggregate and 20% of a "4 s" aggregate (the so-called a-protein). the specimens were prepared eithe ... | 1992 | 1560458 |
| molecular cloning, sequencing and expression in escherichia coli of the odontoglossum ringspot virus coat protein gene. | the sequence of the 3'-terminal 1865 nucleotides of the genome of the tobamovirus odontoglossum ringspot virus (orsv) was determined. this sequence contained two open reading frames (orfs), 912 and 477 nucleotides long. the 912 nucleotide orf has been identified as the cell-to-cell transport protein gene. the 477 nucleotide orf was expressed in escherichia coli, and the product was detected by antibodies specific for the coat protein of orsv. the amino acid sequence of protein encoded by this or ... | 1991 | 1895062 |
| functional analysis of the tobacco mosaic virus trna-like structure in cytoplasmic gene regulation. | the 3'-untranslated region (utr) of tobacco mosaic virus (tmv), which terminates in a trna-like structure, functionally substitutes for a poly(a) tail in both plant and animal cells. the addition of the tmv 3'-utr to chimeric mrna constructs increases their expression up to 100-fold, increasing both translational efficiency and mrna stability. the domain largely responsible for the regulation maps to a 72 base region immediately upstream of the trna-like structure, however, the 3'-terminal, trna ... | 1991 | 1923770 |