10 



CONTROL MECHANISMS IN CELLULAR PROCESSES 



ponent that behaves similarly to a component in highly pm-ified 

 preparations of wild-type Tsase (Carsiotis et ah, 1960). This com- 

 ponent can be resolved on starch electrophoresis and by the use of 

 antigen-antibody reactions in agar gel. The latter is shown in Fig. 

 1-2. Perhaps this component in the CRM-less mutant bears some 

 structural relationship to Tsase. 



Clearly, many types of mutationally altered proteins are formed 

 by Tsase mutants, and it becomes of considerable importance to 



Fig. 1-2. Antigen-antibody reactions in agar gel. Reservoirs: c. anti-Tsase, 

 partially absorbed with fractions of mutant tdj; 1. unabsorbed anti-Tsase; 

 2. Tsase having a specific activity of 225; 3. Tsase having a specific activity of 

 1940; 4. unabsorbed anti-Tsase. 



establish whether mutants with similar protein damage possess de- 

 fects in the same genetic region. On the basis of interallelic crosses 

 in N. crassa and transduction mapping in E. coli, the fine structure 

 of the gene controlling Tsase formation in both organisms is being 

 analyzed. In agreement with the concept of mutations primarily 

 causing substitutions in amino acid sequence, and subsequently in 

 the conformation of the protein, it was found that CRM mutants 

 which produce altered A-proteins with similar properties were clus- 

 tered in particular genetic areas and were not distributed at random 

 throughout the entire Tsase genetic region ( Yanof sky and Crawford, 

 1959; Yanofsky, 1960). From the work of Suyama and Bonner at 

 Yale, it appears that Neurospora CRM mutants which retain the 

 InGP ;=i In + TF reaction are localized in one region of the genetic 



