Figure 1 - full size

Figure 1.
Figure 1. Schematic representation of the biosynthesis of purine nucleotides in S. cerevisiae. For each step, the name of the enzyme and the structural gene (in parentheses) are given. The reaction catalysed by SAICAR synthase is shown in red. Abbreviations: AICAR, phosphoribosylaminoimidazolecarboxamide; AIR, phosphoribosylaminoimidazole; CAIR, phosphoribosylcarboxyaminoimidazole; FAICAR, phosphoribosylformylaminoimidazolecarboxamide; FGAM, phosphoribosylformylglycinamidine; FGAR, phosphoribosylformylglycinamide; GAR, phosphoribosylglycinamide; PR, 5-phosphoribosyl; PRA, phosphoribosylamine; PRPP, 5-phosphoribosyl 1-pyrophosphate.