Ultrastructure Of Bacterial Viruses

Mter the discoveryof the tobacco mosaic virus by D. I. Ivanov skU in 1892 [14], the new science of virology was born and began to develop rapidly. The number of viruses now known is enormous and they can infect nearly all animal and plant organisms. Microorganisms themselves are no exception to this rule. Despite intensive study of Vlruses, their origin and nature are still a subject for speculation and hypothesis. The general concept of viruses embraces a wide group of biologically active structures occupying an intermediate position between living and nonliving matter. The dual character of viruses is determined by the fact that, while they do not possess an inde pendent system of metabolism, which is a characteristic feature of every living being, they nevertheless carry within themselves all the necessary information for autoreproduction. A striking feature of the virus is that it consists essentially of two components: a protein envelope and the nucleic acid con tained within it. In contrast to the elementary structural unit of the living or ganism, the cell, which contains two types of nucleic acid (DNA and RNA), the virus particle contains only one type of nucleic acid - either DNA or RNA. It is perhaps this which is responsible for the imperfection of the virus as a living organism.

Discusses bacteria and viruses.

Virus Structure describes the physical characteristics of isolated viruses that represent typical structural groups, with particular reference to those features analyzed with the aid of the electron microscope. For descriptive purposes, the book has been divided into sections starting with the small icosahedral viruses and leading to the larger and more sophisticated structures, regardless of whether they are animal, plant, or bacterial viruses. These include double-stranded DNA icosahedral viruses, herpesvirus, viruses with helical symmetry, and viruses with complex or a combination of symmetries. Many common architectural features will be found in those viruses selected for discussion in each of the sections, and for these reasons the introduction places some emphasis on the symmetry elements rather than the shapes of viruses. The mechanism by which viruses enter host cells and the events that follow once the cell has been infected are only mentioned briefly as the virus-host interaction is a relatively complex one.

Virus Structure covers the full spectrum of modern structural virology. Its goal is to describe the means for defining moderate to high resolution structures and the basic principles that have emerged from these studies. Among the topics covered are Hybrid Vigor, Structural Folds of Viral Proteins, Virus Particle Dynamics, Viral Gemone Organization, Enveloped Viruses and Large Viruses. Covers viral assembly using heterologous expression systems and cell extracts Discusses molecular mechanisms in bacteriophage T7 procapsid assembly, maturation and DNA containment Includes information on structural studies on antibody/virus complexes