De novo nucleotide synthesis pathways construct nucleotide bases from simple precursor molecules such as amino acids, ATP, and CO2. These newly formed bases are ultimately attached to an activated ribose platform, 5-phosphoribosyl-1-pyrophosphate (PRPP), to form complete nucleotides.

There are two primary strategies for de novo synthesis:

• Pyrimidine de novo synthesis: The pyrimidine base ring is assembled first and subsequently attached to PRPP.
• Purine de novo synthesis: The purine base ring is constructed piece by piece directly onto the pre-existing PRPP structure.