3. De novo purine nucleotide synthesis begins with the transferring of an amino group from GIn to PRPP PRPP is synthesized from ribose 5-P In the first(committing step of purine nucleotide synthesis, the Ppi part on PRPp (at C-1)is replaced by the side chain amino group of gIn forming 5-phosphoribosylamine a glycine(2C +lN), a Ni0-formyl H4 folate(1C),a GIn(IN),a HCO3(1C)Asp(1N),and another N10 formyl H4 folate(1c then brings the rest atoms for the purine ring3. De novo purine nucleotide synthesis begins with the transferring of an amino group from Gln to PRPP • PRPP is synthesized from ribose 5-P. • In the first (committing) step of purine nucleotide synthesis, the PPi part on PRPP (at C-1) is replaced by the side chain amino group of Gln, forming 5-phosphoribosylamine. • A glycine (2C +1N), a N10-formyl H4 folate (1C), a Gln (1N), a HCO3 - (1C) Asp (1N), and another N10- formyl H4 folate (1C) then brings the rest atoms for the purine ring