Chapter X 



Contributions from TMV Studies 



to the Problem of Genetic Information 



Transfer and Codmg 



A. TSUGITA' AND H. FRAENKEL-CONRAT 



Virus Laboralory, 

 University of Calijornia, 

 Berkeley, California 



I. Introduction 



II. TMV-Protein 



A. Rod Structure and Cliain Configuration 



B. Amino Acid Sequence . 



III. TMV-RNA 



I\'. Viral Infectivity .... 



.\. Chemical Basis of Infectivity 



B. Mechani.sm of Infection 



C. Cell-Free Biosynthesis of TMV-Protein .... 

 V. Natural Strains of TMV 



A. Symptomatology of TMV and Its Strains . 



B. Composition of Natural Stra'ns 



C. Mixed Reconstitution 



D. Structural Differences in the RXA of Different Sti'a-ns 

 \T. Chemically Produced Strains 



A. Modification of the RXA 



B. Protein Composition of Chemically Produced Mutants 



C. Virulence and Viability of Strains 



\TI. The Coding Problem 



References 



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I. Introduction 



The firtjt de.sci-iption of a virus as a new kind of biological entity 

 we owe to Iwanowski (1892), and particularly to Beijerinck (1899). 

 who demonstrated that the tobacco mosaic disease was due to a repli- 

 cating substance which was able to pass through bacterial filters. In the 

 following 40 years many plant and animal diseases were attributed to 

 this novel class of agents, termed the filtrable viruses. That bacteria 

 could also harbor viruses was shown by Twort and by d'Herelle about 

 1915. However, until about 1930 few chemists or bioclieniists concerned 

 ' Pre.sent address: Research Institute for Protein, Osaka University, Osaka, Jajian. 



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