Enzymatic synthesis of purine nucleotides.

The demonstration of a pathway of pyrimidine nucleotide synthesis in which PRPP’ is a key intermediate (1, 2) prompted a study to determine whether the same type of reaction mechanism might apply to the synthesis of purine nucleotides. In a preliminary note the condensation of adenine with PRPP to yield A5P was reported (3). Subsequent work has established the existence of enzymes in yeast which react with other purines (hypoxanthine and guanine) and supports a more generalized equation (1).