84 



MICROBIAL CELL WALLS 



UDP 



UTP 



AG-lact-l-P 



UDP-AG-lact 



UDP-AG-lact-6-P 



UTP 



+ AG-l-P 



UDP-AG 



+ Acceptor 



+ Acceptor-AG 



Acceptor-AG-AG-lact + UDP-AG 



1 



UDP-AG-lact-peptide + Acceptor-AG-AG-lact-AG 

 Acceptor- AG-AG-lact-AG-AG-lact-peptide 



Fig. 20. A hypothetical pathway for the biosynthesis of bacterial cell 

 wall. 



countered in higher organisms, for this undoubtedly ac- 

 counted for the great selective toxicity of the antibiotic peni- 

 cillin and probably some of the subsequent antibacterial 

 agents. 



There is little doubt that the next ten years will see an 

 enormous widening of our understanding of both the chemi- 

 cal structure and biosynthesis of these fascinating structures. 

 If, in the process of unraveling these details, we can add a 

 few strokes to our picture of the evolution of microbial 

 structures and the interrelationships of microbial groups, 

 our scientific curiosity will have been amply rewarded. 



