Viruses tobacco mosaic virus

Figure 5.4 Structure and manner of assembly of a simple virus, tobacco mosaic virus, (a) Electron micrograph at high resolution of a portion of the virus particle, (b) Assembly of the tobacco mosaic virion. The RNA assumes a helical configuration surrounded by the protein capsomeres. The center of the particle is hollow.

Murine hepatitis virus Tobacco mosaic virus Mice developed serum IgG and IgA specific for Protective in mice immunized parenterally 105... 

Viral coat proteins, see Southern bean mosaic virus, Tobacco mosaic virus, or Tomato bushy stunt virus... 

Stanley first crystallized a virus, tobacco mosaic virus. 1937... 

Creager, Angela N. H. 2002. The Life of a Virus Tobacco Mosaic Virus as an Experimental Model, 1930-1965. Chicago University of Chicago Press. 

Mice Cytomegalovirus Murine Sarcoma Virus Measles Virus Newcastle Disease Virus Pokeweed Antiviral Proteins Pseudorabies Virus Ribosome-Inactivating Proteins Respiratory Syncytial Virus Reverse Transcriptase Sindbis Virus Tobacco Mosaic Virus Vesicular Stomatitis Virus Vaccinia Virus Varicella Zoster Virus... 

Unaware of the underlying principle this was first used by Cohen already in 1941 [87] to separate two viruses Tobacco Mosaic Virus and Tobacco Necrosis Virus. Tobacco Mosaic Virus is a rod-Uke vims with a length of 300 nm and diameter of 18 nm and Tobacco Necrosis Vims a spherical virus with a diameter of about 26 nm. Cohen used the polysaceharide heparin as depletant to separate these viruses. Recently, this method to separate eoUoids of different size and shape has gained new impetus. For nano-based teehnologies partieles with a specific size and shape are critical to optimize the nanostrueture-dependent optieal, electrical and magnetic properties. 

The RNA molecule of one of the most thoroughly studied viruses, tobacco mosaic virus (TMV), has the structure of a single-stranded polynucleotide consisting of approximately 6000 nucleotides. The fact that this RNA contains the information determining amino acid sequence in the protein of the virus coat (158 amino acid residues in each protein molecule) is shown not only by the widely known and extensive data on infectivity of pure tobacco mosaic virus RNA and its ability to reproduce whole virus, but also, in a more direct form, by investigations of inherited changes in the amino acid sequence of this protein as a result of experimental modifications of flie nucleotide composition of the virus RNA by the action of nitric acid and other substances under carefully controlled conditions. Such treatment causes deamination... 

Isolation of the first crystallized virus Tobacco mosaic virus (Stanley)... 

Bloomer, A.C., et al. Protein disk of tobacco mosaic virus at 2.8 A resolution showing the interactions within and between subunits. Nature TIB-. 362-368, 1978. 

A nucleic acid can never code for a single protein molecule that is big enough to enclose and protect it. Therefore, the protein shell of viruses is built up from many copies of one or a few polypeptide chains. The simplest viruses have just one type of capsid polypeptide chain, which forms either a rod-shaped or a roughly spherical shell around the nucleic acid. The simplest such viruses whose three-dimensional structures are known are plant and insect viruses the rod-shaped tobacco mosaic virus, the spherical satellite tobacco necrosis virus, tomato bushy stunt virus, southern bean mosaic vims. 

Antiparallel tt-helix proteins are structures heavily dominated by a-helices. The simplest way to pack helices is in an antiparallel manner, and most of the proteins in this class consist of bundles of antiparallel helices. Many of these exhibit a slight (15°) left-handed twist of the helix bundle. Figure 6.29 shows a representative sample of antiparallel a-helix proteins. Many of these are regular, uniform structures, but in a few cases (uteroglobin, for example) one of the helices is tilted away from the bundle. Tobacco mosaic virus protein has small, highly... 

Extracts from 152 plant species, representing 46 different families, were screened for effects on tobacco mosaic virus (TMV) replication in cucumber cotyledons. Twenty species have shown enough activity to warrant further study. Several members of the Caprifoliaceae family increased virus replication. An extract of Lonicera involucrata enlarged the virus lesions in local lesion hosts and produced a thirty fold increase in virus titer, but had no effect on virus replication in systemic hosts. The active material appears to affect the virus defense mechanism of local lesion hosts. An extract of common geranium is an active virus inhibitor. It inactivates TMV and TMV-RNA (ribonucleic acid) in vitro by forming non-infectious complexes. In vivo, it also inhibited starch lesion formation in cucumber cotyledons incited by TMV infection. 

Cucumber cotyledons were inoculated with purified tobacco mosaic virus (TMV) 20 to 24 hours before vacuum infiltration with different concentrations of crude water extracts of plant leaves (4). After 7 days, inoculated leaves were harvested and stored 24 hours in the dark in a moist chamber to remove excess starch. Starch lesions were counted after clearing with alcohol and staining with an iodine-potassium iodide-lactic acid mixture. The inhibitory effects of various extracts were demonstrated by comparing lesion counts of treated cotyledons to counts on control cotyledons. 

Fraser, R.S.S. (1982). Are pathogenesis-related proteins involved in acquired systemic resistance of tobacco plants to tobacco mosaic virus Journal of General Virology, 58, 305-13. 

Whenham, R.J., Fraser, R.S.S., Brown, L.P. Payne, J.A. (1986). Tobacco-mosaic-virus-induced increase in abscisic-acid concentration in tobacco leaves Intracellular location in light and dark-green areas, and relationship to symptom development. Planta, 168, 592-8. 

Some virus particles have their protein subunits symmetrically packed in a helical array, forming hollow cylinders. The tobacco mosaic virus (TMV) is the classic example. X-ray diffraction data and electron micrographs have revealed that 16 subunits per turn of the helix project from a central axial hole that runs the length of the particle. The nucleic acid does not lie in this hole, but is embedded into ridges on the inside of each subunit and describes its own helix from one end of the particle to the other. 

Putting aside such considerations, the reader is encouraged to examine the sections of Klug s Nobel Lecture 1W) dealing with the structure and the growth of Tobacco Mosaic Virus to see how helical structures and concepts of inclusion phenomena can relate to molecular biology. 

Santos NC and Castanho MARB. 1996. Teaching light scattering spectroscopy The dimension and shape of tobacco mosaic virus. Biophysical Journal 71(3) 1641-1650. 

Yi L, Shi J, Gao S et al (2009) Sulfonium alkylation followed by click chemistry for facile surface modification of proteins and tobacco mosaic virus. Tetrahedron Lett 50 759-762... 

Schlick TL, Ding Z, Kovacs EW, Francis MB (2005) Dual-surface modification of the tobacco mosaic virus. J Am Chem Soc 127 3718-3723... 

A typical virus with helical symmetry is the tobacco mosaic virus (TMV). This is an RNA virus in which the 2130 identical protein subunits (each 158 amino acids in length) are arranged in a helix. In TMV, the helix has 16 1/2 subunits per turn and the overall dimensions of the virus particle are 18 X 300 nm. The lengths of helical viruses are determined by the length of the nucleic acid, but the width of the helical virus particle is determined by the size and packing of the protein subunits. 

Ribonuclease (RNase) reconstruction The tobacco mosaic virus... 

Completely different mechanisms are involved in the self-assembly of the tobacco mosaic virus (TMV). This virus consists of single-strand RNA, which is surrounded by 2,130 identical protein units, each of which consists of 158 amino acid residues. A virus particle, which requires the tobacco plant as a host, has a rodlike structure with helical symmetry ( Stanley needles ). It is 300 nm long, with a diameter of 18nm. The protein and RNA fractions can be separated, and the viral... 

Nagata, T., Okabe, K., Takebe, I. and Matsui, C. (1981). Delivery of tobacco mosaic virus RNA into plant protoplasts mediated by reverse-phase evaporation vesicles (liposomes). Mol. Genet. Genomics 184, 161-5. 

Perham, R.N., and Thomas, J.O. (1971) Reaction of tobacco mosaic virus with a thiol-containing imi-doester and a possible application to X-ray diffraction analysis./. Mol. Biol. 62, 415—418. 

Antibody, murine IgG-2b/K, against tobacco mosaic virus Suspension Nicotiana tabacum (tobacco) A. tumefaciens transformation of leaf explant CaMV 35 S Murine 15 4g g 1 wet weight (i) 45 4g g 1 wet weight (i) with amino acids 62... 

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