525 



Purines 



alcohols in the presence of sulfokinases. The generality 

 of the sulfate transfer mechanism has been demonstrated 

 in yeast, neurospora and liver. 



The recognition of S-adenosylmethionine as the active 

 complex in methyl group transfer from methionine (and 

 perhaps in its biosynthesis) was noted in the section on 

 amino acids. 



In the section on aliphatic acids an ATP requirement 

 was noted in the formation of acyl coenzyme A. A num- 

 ber of acyl adenylates have been prepared or isolated 

 from natural sources.^' "*■ ^ These can be converted en- 

 zymically into acyl coenzyme As. The general structure 

 of these activated acids is: 



R— C- 



NH2 



O 



T 



-0— P— O— CH; 



I 



OH 



&^^ 



K^ 



OH OH 



Acid Anhydrides of 

 Adenosine-5'-pliosphate 



3 Paul Berg, ibid. 77 3163 (1955). 



■* Preston T. Talbert and F. M. Huennekens, ibid. 78 4671 (1956). 



•■^C. H. Lee Peng, Biochim. et Biophys. Acta 22 42 (1956). 



