NUCLEIC ACIDS AND AMINO ACID 

 INCORPORATION 



E. F. Gale 



Medical Research Council Unit for Chemical Microbiology, Department of 



Biochemistry, University of Cambridge 



In order to investigate the biological functions of nucleic 

 acids, it is necessary to devise preparations of cells in which 

 it is possible to modif}^ the nucleic acid components without 

 affecting other factors involved in relevant biochemical 

 activities. Although the actions of transforming principles 

 are demonstrated in growing cultures, intact cells in general 

 do not appear to be permeable to nucleic acids and, conse- 

 quently, the actions of the latter must be studied in subcellular 

 preparations. Since the demonstration that suitable prepara- 

 tions could be obtained from broken staphylococcal cells 

 (Gale and Folkes, 1953a), a number of other subcellular 

 materials have been obtained in which direct investigation of 

 nucleic acid function is possible (Allfrey, 1954; Beljanski, 

 1954; Lester, 1953; Littlefield et al., 1955; Nisman, Hirsch and 

 Marmur, 1955; Nisman, Hirsch, Marmur and Cousin, 1955; 

 Webster and Johnson, 1955; Zamecnik and Keller, 1954). 

 As a result of investigations with these preparations it has 

 been found that the incorporation of labelled amino acids is 

 dependent upon the presence of nucleic acids and that, in 

 appropriate structures, the process can be mediated by ribo- 

 and by deoxyribonucleic acid (Gale, 1956a). The purpose 

 of this contribution is to discuss what we ourselves have 

 learned of the function of nucleic acids in amino acid incor- 

 poration studied in disrupted staphylococcal cells, and 

 consists largely of a summary of material recently pub- 

 lished elsewhere (Gale and Folkes, 1955a and b; Gale, 1956a 

 and b). 



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