THE PROBLEM OF NUCLEOTIDE SEQUENCE IN DEOXYRIBONUCLEIC ACIDS 79 



SOLITARY PY. NUCLEOTIDES IN RYE GERM DNA & FRACTIONS 



BASES , MOLE % IN DNA 



DIPHOSPHATES, % OF BASES 

 5 10 15 20 25 



TOTAL RGDNA 

 RGDNA-0.60 

 RGDNA- 0.65 

 RGDNA- 0.70 

 RGDNA- 0,75 

 RGDNA- 0.80 

 RGDNA- 0.90 

 RGDNA- 170 



27.4 



16 4 



5 9 



26 3 

 17.0 

 6.8 



27.1 



16.2 

 6.4 



28.2 



16.6 



6.1 



27.8 

 16.6 

 5.8 



28.0 

 16.8 

 6, I 



28.6 



16.5 



5.4 



29.2 

 15 8 

 4.7 



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,T 



D , C 



, M 



Fig. 2. Pyrimidine distribution analysis of the total deoxyribonucleic acid of 

 rye germ and its fractions. The first column indicates the NaCl molarity at which 

 dissociation of the fraction from its histone salt occurred. The second column 

 summarizes the composition of the specimens in terms of the molar concentrations 

 (per 100 gm.-at. of nucleic acid P) of thymine (T), cytosine (C), and 5-methylcy- 

 tosine (M). The histogram shows the frequency of the solitary nucleotides, isolated 

 as the nucleoside 3 ',5 '-diphosphates, relative to the total concentration of the con- 

 stituent in the nucleic acid. Based on previously published data [37]. 



NUCLEOTIDE ARRANGEMENT IN A MICROBIAL DEOXYRIBONUCLEIC ACID 



OF THE GC TYPE 



Our survey has so far all been dealing with deoxyribonucleic acids 

 that belonged to the AT type. It was of interest to see whether the same 

 considerations could be applied to a nucleic acid of the GC type, i.e., 



