Studies on the Incorporation of Arginine into Acceptor 

 RNA of Escherichia coli* 



H. G. BOMAN, I. A. BOMANf 



The Rockefeller Institute, New York, U.S.A. 



and 



W. K. Maas| 



New York University College of Medicine, 

 New York, U.S.A. 



Introduction 



The activation of amino acids and their transfer to acceptor RNA 

 (soluble RNA, sRNA) has been extensively investigated in several labora- 

 tories (for a review see Zamecnik [i]). Although it is generally assumed that 

 these reactions are involved in the biosynthesis of proteins, relatively 

 little experimental evidence from whole cell studies is available on the 

 exact nature of their participation [2]. To characterize further the role of 

 these reactions in cellular metabolism we began a study of the incorpora- 

 tion of arginine into acceptor RNA. It has been shown that in E. colt 

 the intracellular concentration of this amino acid controls the formation 

 of enzymes involved in its own biosynthesis [3]. When the concentration 

 of arginine is high, such as in cultures growing in the presence of exo- 

 genously provided arginine, the formation of these enzymes is repressed ; 

 when it is low, as in an arginine-requiring mutant growing with limiting 

 arginine in a chemostat, the level of enzymes rises to 500 times that of the 

 repressed culture. In view of recent studies which have implicated RNA 

 in the regulation of protein synthesis [4, 5] we felt that the arginine system, 

 in which it is possible to vary the rate of formation of certain specific 

 enzymes, would be suitable to elucidate a possible regulatory function of 

 RNA. 



The present paper is chiefly a description of a system for the in vttro 

 incorporation of arginine into the acceptor RNA. Certain compounds 



* This work was supported by grant no RG-6048 from the U.S. Public Health 

 Service. 



f Present address : Institute of Biochemistry, Uppsala, Szceden. 

 % Senior Research Fellow, U.S. Public Health Service. 



