Figure 4

Purine salvage and purine biosynthesis de novo in yeast Saccharomyces cerevisiae. Intermediates of the purine biosynthesis de novo are designated in blue. The salvage pathway is presented in black. Genes, whose deletions lead to HAP and/or AHA sensitivity are highlighted by red boxes. The proposed conversions of HAP and AHA are represented in brackets below the adenine and guanine metabolites, respectively. Dashed arrows represent hypothetical pathways that were not demonstrated experimentally for a given substrate. Abbreviations:Purine biosynthesis de novo: PRPP – 5-phospho-ribosyl-1α-pyrophosphate, PRA – 5-phospho-β-D-ribosylamine, GAR – 5-phosphoribosylglycinamide, FGAR – 5'-phosphoribosyl-N-formyl glycinamide, FGAM – 5'-phosphoribosyl-N-formylglycinamidine, AIR – 5'-phosphoribosyl-5-aminoimidazole, CAIR – 5'-phosphoribosyl-5-aminoimidazole-4-carboxylate, SAICAR – 5'-phosphoribosyl-4-(N-succinocarboxamide)-5-aminoimidazole, AICAR – 5'-phosphoribosyl-4-carboxamide-5-aminoimidazole, FAICAR – 5'-phosphoribosyl-4-carboxamide-5-formamidoimidazole, SAMP – adenylosuccinate, 5,10-methylene-THF – 5,10-methylenetetrahydrofolate, 10-formyl-THF – 10-formyltetrahydrofolate. Salvage: Ade – adenine, AdeRib – adenosine, Hyp – hypoxanthine, Gua – guanine, Xan – xanthine.