458 F. B. STRAUB 



It is tempting to apply the same hypothesis to the formation of inducible 

 enzymes. In our laboratory Dr Kramer made the very important observation, 

 that an inducible strain of Bacillus cereus will start synthesizing peniciUinase if 

 it is treated under appropriate conditions with an extract containing a specific 

 RNA prepared from a strain which has the property of forming penicillinase [lo, 

 II, 12]. I do not want to go into the details of this work, which has already been 

 pubhshed, but it must be clear that this phenomenon has nothing to do with the 

 known transformations which were obtained with DNA preparations. Our case 

 is in essence an induction of the synthesis of an enzyme without inductor but 

 with a specific RNA. 



Naturally only such strains of B. cereus may be used with success, which are 

 inducible, i.e. genetically determined as being able to produce the enzyme. In 

 my opinion the genetic determination, of being inducible or not, may be ex- 

 plained by the presence or absence of a protein precursor which can be trans- 

 formed into penicillinase. 



Earlier work on the formation of /3-galactosidase seems to have eliminated 

 this hypothesis but the experimental proof is not convincing. What has been 

 proved is only that the hypothetical precursor does not exist in a measurable 

 concentration. But this is no objection if we suppose that the same precursor, 

 which upon induction gives rise to the induced enzyme protein is converted in 

 uninduced cells into some other specific protein, i.e. into the PZ protein in the 

 case of Escherichia coli. 



I am aware that our views are not in accord with current trends in the field of 

 protein biosynthesis. Nevertheless, only further work can decide how far the 

 assumption of intermediary stages in protein synthesis can help in clarifying the 

 comphcated biochemical and genetical problems involved. Looking now at the 

 problem of the origin of life I should like to present a few remarks on the prob- 

 lem of the origin of the enzymes. 



Every year brings out a startling crop of new enzymic activities detected in 

 simple organisms, so that it is quite impossible to imagine that such a living 

 system could have arisen from the non-living. We have to assume that the 

 primary forms have been heterotrophic to a very much greater extent than is 

 known to us to-day. This I beheve is not against common sense. Organic com- 

 pounds are very unstable at the present day, when existing living forms avidly 

 destroy and use up any organic material with which they come into contact. 

 However, before the appearance of life, those organic compounds, which had 

 been accidentally synthesized by inorganic catalysts, must have accumulated all 

 the time. 



They may have accidentally been concentrated at some spots and thus might 

 have realized the conditions necessary for the reduplication of the simplest 

 living substance. 



The point I want to make is, that the most primitive living system need not 

 have had a broad spectrum of enzymes, it would perhaps have been enough to 

 have a most primitive structure which coupled a breakdown process with a 

 synthetic one producing a limited number of peptide chains. In this case it is 

 supposed that the environment contained all the organic substances necessary 



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