Viruses Molecular biology

The original Central Dogma of molecular biology (left) and its modification in light of the discovery of viruses (right). 

Spom, M.B.. Roberts, A.B., Wakefield, L.M.. de Crombrugghe, B. (1987). Some recent advances in the chemistry and biology of transforming growth factor beta. J. Cell Biol. 105, 1039-1045. Tooze, J. (1973). The Molecular Biology of Tumor Viruses. Cold Spring Harbor Laboratory. Cold Spring Harbor, New York. 

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. 

Viruses are classified initially on the basis of the hosts they infect. Thus we have animal viruses, plant viruses, and bacterial viruses. Bacterial viruses, sometimes called bacteriophages (or phage for short, from the Greek phago meaning to eat), have been studied primarily as convenient model systems for research on the molecular biology and genetics of virus reproduction. Many of the basic concepts of... 

When a virus multiplies, the genome becomes released from the coat. This process occurs during the infection process. The present chapter is divided into three parts. The first part deals with basic concepts of virus structure and function. The second part deals with the nature and manner of multiplication of the bacterial viruses (bacteriophages). In this part we introduce the basic molecular biology of virus multiplication. The third part deals with important groups of animal viruses, with emphasis on molecular aspects of animal virus multiplication. 

We have discussed in a general way the nature of animal viruses in the first part of this chapter. Now we discuss in some detail the structure and molecular biology of a number of important animal viruses. Viruses will be discussed which illustrate different ways of replicating, and both RNA and DNA viruses will be covered. One group of animal viruses, those called the retroviruses, have both an RNA and a DNA phase of replication. Retroviruses are especially interesting not only because of their unusual mode of replication, but because retroviruses cause such important diseases as certain cancers and acquired immunodeficiency syndrome (AIDS). 

When genetic information (nucleic acid) is transferred between different cells, species or genera it is often carried by a specialized DNA molecule called a vector. Viruses are natural vectors, as are some kinds of small independently replicating circular extra-chromosomal DNA molecules (plasmids). A few of the basic features of plasmids used in molecular biology are reviewed in Figure 2.6. 

Elint SJ (2004) Principles of virology molecular biology, pathogenesis, and control of animal viruses. ASM, Washington DC... 

The Baculoviridae are a family of large enveloped DNA viruses that are characterised by rod-shaped nucleocapsids and relatively large double stranded DNA genomes. Autographa californica Multicapsid Nuclear Polyhedrosis Virus (AcMNPV) is the baculovirus most currently used as vector for protein production with insect cells. Several reviews are available describing baculovirus structure and its molecular biology [6-8]. 

Du Pont s medical diagnostics and pharmaceutical businesses are underpinned by substantial basic research in molecular biology and biochemistry. For example, Du Pont recently announced an improved, more reliable test for detection of antibodies to the virus that causes acquired immunodeficiency syndrome. In another program the protein interleukin-2 produced in Du Pont s laboratories by recombinant DNA methods is being used in some very promising cancer research. 

Research into the chemistry of template-dependent nucleic acid biosynthesis, combined with modern techniques of molecular biology, has elucidated the life cycle and structure of the human immunodeficiency virus, the retrovirus that causes AIDS. A few years after the isolation of HIV, this research resulted in the development of drugs capable of prolonging the lives of people infected by HIV. 

Stephenson, J. R., ed. (1980) Molecular Biology ofRNA Tumor Viruses, Academic Press, New York... 

The small pieces of DNA known as plasmids, which replicate independently of the chromosomes, have been discussed briefly in Chapter 5. Plasmids share a number of properties with viruses, and both are important to the techniques of contemporary molecular biology and genetic engineering. Bacterial plasmids may be present as one or several copies for each chromosome. Episomes are plasmids that are able to become integrated into the bacterial chromosome. Some extrachromosomal elements are episomes in one host and plasmids in another. Bacterial... 

Hayes, W. (1968) The Genetics of Bacteria and Their Viruses Studies in Basic Genetics and Molecular Biology, 2nd ed., Wiley, New York... 

Just as threatening is the possibility of biochemical warfare, e.g., the use of artificial viruses. Biological weapons have been little used because of their lack of discrimination between friend and foe. However, our increasing knowledge of molecular biology makes possible insidious attacks on a population of unvaccinated persons. Since biochemical work does not require elaborate facilities, the development of biological weapons can be carried on by small groups in a clandestine manner. The recent assembly of a viable... 

Greene WC. 1991. The molecular biology of human immunodeficiency virus type 1 infection. N Engl J Med. 324 308-317. 

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