Guanylate synthesis from inosinate

The glutamine analogue, diazo-oxo-norleucine, and the aspartate analogue, hadacidin (iV-formyl hydroxyaminoacetic acid), inhibit guanylate synthetase and adenylosuccinate synthetase, respectively. Alanosine (2-amino-3-nitrohydroxylaminopropionic acid) is also an inhibitor of adenylate synthesis from inosinate, but its mechanism of inhibition is not yet clear (52). 

The synthesis of adenylate from inosinate in bone marrow and microbial preparations, and of guanylate from inosinate in pigeon liver, bone marrow, and bacterial extracts were reported between 1955 and 1957 (see references 2, 6-10). In the course of these studies, two new purine ribonucleotides were identified and shown to be intermediates in these processes. 

The conversion of adenine to guanylate does not involve the reversal of the steps leading from inosinate to adenylate, for these reactions strongly favor adenylate synthesis. However, mutants blocked in one of these... 

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