Tobacco mosaic virus, organization

The satellite ssRNA viruses are a group of ssRNA icosahedral viruses, which are the satellites to certain plant viruses (Pritsch and Mayo, 1989). Satellite tobacco necrosis virus (STNV), a satellite virus to tobacco necrosis virus, was in fact one of the first icosahedral virus structures to be determined by X-ray crystallography (Liljas et al, 1982). In more recent years, two other satellite plant viruses, satellite tobacco mosaic virus (STMV) (Larson et al, 1993, 1998) and satellite panicum mosaic virus (SPMV) (Ban and McPherson, 1995), have been determined. These are perhaps the simplest and smallest icosahedral viruses whose structures have been determined by X-ray crystallography. Of relevance to our discussion is the structure of STMV determined to 1.8-A resolution, which shows extraordinary details about genome organization (Larson et al, 1998 Larson and McPherson, 2001). 

Genes in all cellular organisms are made of DNA. The same is true for some viruses, but for others the genetic material is RNA. Viruses are genetic elements enclosed in protein coats that can move from one cell to another but are not capable of independent growth. One well-studied example of an RNA virus is the tobacco mosaic virus, which infects the leaves of tobacco plants. This virus consists of a single strand of RNA (6930 nucleotides) surrounded by a protein coat of 2130 identical subunits. An RNA-directed RNA polymerase catalyzes the replication of this viral RNA. 

An enormous number of viruses have been identified since 1892, when the Russian researcher Dmitri Ivanovski first isolated the tobacco mosaic virus. Because their origins and evolutionary history are unclear, the scientific classification of viruses has been difficult. Often, viruses have been assigned to groups according to such properties as their microscopic appearance (e.g., rhabdoviruses have a bullet-shaped appearance), the anatomic structures where they were first isolated (e.g., adenoviruses were discovered in the adenoids, a type of lymphoid tissue), or the symptoms they produce in a host organism (e.g., the herpes viruses cause rashes that spread). In recent years, scientists have attempted to develop a systematic classification system based primarily on viral structure, although several other factors are also important (e.g., host and disease caused). 

It fits nicely into the picture of dual structure-phase views of biomesogenic organizations that objects of rod-like appearance , for instance the little world of the tobacco mosaic virus (which - its overall design reduced to a simple rod-like entity - became the starting point of Onsager s theory [37]), as well as much simpler protein and nucleic acid helices are typical mesophase formers in the classical liquid-crystal phase... 

Isolation of tobacco mosaic virus under the electron microscope Suggested that an organism could be produced by transplanting the nucleus (i.e. the DNA) of a cell from one human to the egg of another Synthesis of Vitamin B2 (Riboflavin)... 

Shenton W, et al. Inorganic-organic nanotube composites from template mineralization of tobacco mosaic virus. Adv Mater 1999 11 253-6. 

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