Studies on the Mechanism of Synthesis of 

 Soluble Ribonucleic Acid* 



E, S. CANELLAKIsf AND EdWARD HERBERT 



Departmeni of Pharmacology, Yale University 



Medical School, New Haven, Conn., U.S.A. 



and 



Department of Biology, Massachusetts 



Institute of Technology, Cambridge, Mass. U.S.A. 



Our studies have been concerned with the mechanism of synthesis of 

 the soluble RNA (S-RNA) present in the soluble cytoplasmic fraction of 

 rat liver. In this fraction of rat liver, enzymes concerned with the in- 

 corporation of ribonucleotides into terminal positions of S-RNA have also 

 been found. Within the allotted space I shall attempt to present a summary 

 of our studies on the synthesis of soluble-RNA, rather than present in 

 detail any one particular aspect of the problem. 



I. Fractionation of ribonucleotide 

 incorporating enzyme and S-RNA 



By a series of fractionation techniques outlined in Table I and Figs, i 

 and 2, we have been able to achieve an approximately roc 200 fold 

 purification of three protein and S-RNA components from rat liver. 

 These three fractions have been termed S-RNA-proteins a-, ^- and -y 

 based on the order of their elution off the hydroxylapatite columns. Each 

 of these fractions will incorporate ribonucleotides into the corresponding 

 S-RNA in terminal positions. We have been further able to separate the 

 protein from the S-RNA by the use of diethylaminoethylcellulose (DEAE) 

 (Fig. 3). Thus separated, neither the RNA nor the protein by itself will 

 incorporate ribonucleotides into an acid insoluble form; full activity is 

 restored upon recombination of the protein and the S-RNA. 



* Detailed experimental evidence for the material published in this summary 

 may be found in the following articles which have been published or are in press. 

 Canellakis, E. S., and Herbert, E., Proc. nat. Acad. Set., Wash. 46, 170 (i960); 

 Herbert, E., and Canellakis, E. S., Biochim. b/ophys. Acta 42, 363 (i960) ; Canellakis, 

 E. S., and Herbert, E. (S-RNA H, IV, V), Biochim. biophys. Acta 45, 133 (iq6o), 

 47, 78 (1961), 47, 85 (1961). 



t Senior Research Scholar of the U.S.P.H.S. wishes to thank this Service for 

 financial aid associated with this trip to Stockholm, Sweden. 

 I 



