. . "dataSource ADDED by a reasoner: http://pid.nci.nih.gov/biopaxpid_4"^^ . . . "PRPP"^^ . "5-phospho-alpha-D-ribose 1-diphosphate"^^ . "5-Phosphoribosyl 1-pyrophosphate"^^ . "5-Phosphoribosyl diphosphate"^^ . .