160 



S. S. COHEN 



f^ IpC-OH HO-P-O-P-O-C O f^ \ C— C-C-CHPPO3H2 



+ I 



NH2 OH 



Anthranilic 

 acid 



Tryptophan 



I 

 HCOH 



I 

 HCOH 



— PP 



HC— 



I 

 H2COPO3H2 



+ Serine 



(XVII) 



OH .OH 

 ^ / 

 -C- 

 H H 



H Indoleglycerophosphate 



r^ 





• Glycerophosphate 



C 



II Indole 



In the formation of histidine (Moyed and Magasanik, 1957) the reaction 

 involves the participation of adenylic acid and glutainine, as shown in 

 formula (XVIII). 



ATP 



^^ JK / Ribose P 

 N N 

 I 



Histidine 



H2O3POH2C-C-C— C=CH , 

 1 'ill I + 



ohohI^^^Ijh 



Imidazole glycerophosphate 

 (XVIII) 



Pyrophosphoryl ribose phosphate also reacts with glutamine to form the 

 starting phosphoribosyl amine on which pm-ine bases are constructed, as 

 shown in formula (XIX). 



