USE OF EXOGENOUS PURINES AND PURINE NUCLEOTIDES IN THE BIOSYNTHESIS OF NUCLEIC ACIDS IN PLAGUE BACTERIA

The purpose of the present investigation was to determine the capacity of the plague microbe to assimilate and inter-convert purines and purine nucleotides in the process of biosynthesis of nucleic acids. Conclusions were as follows: The plague microbe (EV strain), in spite of the capacity to synthesize purines de novo and the presence in the cells of a background of precursors of purines of nucleic acids, readily incorporates exogenous purines into the polynucleotides; these are adenine, guanine, hypoxanthine, and xanthine. All or almost all the adenine of freshly synthesized nucleic acids is formed from exogenous adenine. Exogenous xanthine may be the main source of guanine of nucleic acids. The plague microbe does not possess the capacity to convert exogenous adenine to guanine and weakly converts exogenous guanine to adenine of polynucleotides.