no 



PETER REICHARD 



in the system. I should hke to stress the point that the reduction of ribo- 

 nucleotides was controlled not only by the product-deoxynucleotide of the 



Fig. 9. Effects of deoxynucleoside triphosphates on DNA formation from 

 GMP. Conditions as in Fig. i with labelled GMP in place of CMP; individual 

 deoxynvicleoside triphosphates added as indicated on the abscissa. 



Mxio^ 



Fig. 10. Effects of deoxynucleoside triphosphates on the reduction of GMP. 

 The conditions of incubation and of the assay were as described in an earlier 

 paper [5]. 



respective reactions, but also by the other deoxynucleotides ; e.g. dATP 

 and dGTP greatly inhibited the reduction of CMP, and the pyrimidine 

 deoxyribonucleotides stimulated the reduction of GMP. 



