deoxyribonucleotide

Deoxyribonucleotide is a nucleotide that contains deoxyribose as its sugar and a nitrogenous base (adenine, cytosine, guanine, or thymine) linked to one to three phosphate groups. When phosphorylated to monophosphate form, the molecules are dAMP, dCMP, dGMP, and dTMP; the diphosphate forms are dADP, dCDP, dGDP, and dTDP; and the triphosphate forms are dATP, dCTP, dGTP, and dTTP. The 2' position of the sugar lacks a hydroxyl group, distinguishing deoxyribonucleotides from ribonucleotides found in RNA.

Deoxyribonucleotides are the monomers that constitute DNA. DNA synthesis uses the deoxyribonucleotide triphosphates (dNTPs) as substrates for DNA polymerases, which catalyze the addition of the deoxyribonucleotide monophosphate to the growing chain and release pyrophosphate. The resulting polymer forms phosphodiester bonds between adjacent nucleotides, enabling the two-stranded helical structure of DNA.

In cells, intracellular pools of deoxyribonucleotides are maintained by ribonucleotide reductase, which converts ribonucleoside diphosphates to deoxynucleoside diphosphates, followed by phosphorylation to the corresponding monophosphates and triphosphates. Salvage pathways also recycle deoxynucleosides. Proper balance of dNTP pools is essential for accurate DNA replication and repair; imbalance can lead to mutagenesis and genome instability. Deoxyribonucleotides are essential substrates for DNA synthesis and repair across organisms.