Main Reaction: guanine + 5-phosphoribosyl 1-pyrophosphate >> GMP

Reference: PubMed ID: 18612078
Authors: Kowalski D, Pendyala L, Daignan-Fornier B, Howell SB, Huang RY
Title: Dysregulation of purine nucleotide biosynthesis pathways modulates cisplatin cytotoxicity in Saccharomyces cerevisiae.
Published: 2008 Oct

guanine + 5-phosphoribosyl 1-pyrophosphate --> GMP