B. REVEL HR, B. Magasanik
Aug 1, 1958
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0
Influential Citations
15
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Journal
The Journal of biological chemistry
Abstract
Histidine is converted by extracts of liver tissue and by extracts of histidine-grown bacteria to the same product, L-C+ formamidinoglutaric acid (2-4). Liver extracts catalyze the formylation of tetrahydrofolic acid by this compound (5, 6) and the transfer of the formyl group from formyltetrahydrofolic acid to the purine precursors N-glycyl-5-phosphoribofuranosylamine, and 4-amino-5-imidazole-carboxamideribonucleotide (7, 8). These observations may explain the earlier finding that in animals carbon atom 2 of the imidazole ring of histidine is an efficient precursor of carbons 2 and 8 of the purine ring (9-11). Bacterial extracts, in contrast to those of animal tissues, catalyze the degradation of n-c+formamidinoglutaric acid in the absence of added formyl carriers; the products of this degradation are glutamic acid and formamide, or glutamic acid, formic acid, and ammonia, depending on the organism (2, 4, 12). It seemed, therefore, of interest to investigate the role of histidine as precursor of purines in bacteria. The results presented in this paper indicate that of the bacteria tested, only those that liberate the amidine carbon of histidine as formic acid can utilize this carbon atom for the synthesis of purines; this single carbon unit is incorporated almost exclusively into carbon 8 of the purine ring, and not into carbon 2.