531 



Purines 







i 

 HC- 



V 



CH 



©. 



H,N' 



OaPOCHj 



OOC 



XD3POCH, 



\^. 



CH 



CO. 



biotin 



OH OH 

 Aminoimidazole 

 Ribotide 



OH OH 



5-Amino-4-imid- 



azolecarboxylic 



Acid Ribotide 



O 



II 



,c. 



HoN 



^, 



CH 



© H.N' 



O3POCH2 



Fumarate 



OH OH 

 5-Amino-4-imidazole- 

 carboxamide Ribotide 



Aspartate--^ I ^ ATP + H2O 



S..ADP + HPOr 



COO® 



I 



CH2 



I 



CH— NH- 

 COO® 



o 

 -c 



:. H2N' 



OaPOCH. 



/ 



OH OH 



5-Amino-4-imidazole- 



N-succinocarboxamide 



Ribotide 



Sulfanilamide and other sulfa drugs inhibit the growth 

 of many bacteria by interfering with the incorporation 

 of p-aminobenzoic acid into the folic acid coenzymes 

 (p-aminosalicylic acid, etc., may do the same in mycobac- 

 teria), and E. coli cultures so inhibited accumulate isola- 

 ble quantities of 5-amino-4-imidazolecarboxamide ribo- 

 tide.-' 



2^ Joseph S. Gots and Edith G. GoUub, Proc. Nat. Acad. Sci. U. S. 

 43 826 (1957). 



