deoxyribose5phosphate

Deoxyribose-5-phosphate, often abbreviated as dR5P or 2-deoxyribose-5-phosphate, is the 5-phosphate ester of 2-deoxyribose, a five‑carbon sugar that lacks the 2′ hydroxyl group found in ribose. It is an important intermediate in the biosynthesis of deoxyribonucleotides, the building blocks of DNA.

Biosynthesis and metabolic context: In cellular metabolism, the deoxyribose backbone required for DNA precursors is supplied through pathways that connect the pentose phosphate pathway with nucleotide synthesis. Ribonucleotide reductase and related enzymes modify ribose-containing intermediates to generate deoxyribose-containing species, with deoxyribose-5-phosphate serving as a key precursor for further conversion into deoxyribonucleotides. The sugar phosphate can be interconverted with other pentose phosphate intermediates by enzymes such as phosphopentomutase, helping coordinate flux between nucleotide building blocks and general carbohydrate metabolism.

Role in nucleotide biosynthesis: Deoxyribose-5-phosphate provides the deoxyribose sugar moiety that is ultimately incorporated into deoxyribonucleotides (dNTPs) used for DNA replication and repair. Its availability and regulation reflect the cell’s need to balance DNA synthesis with overall nucleotide and energy metabolism.

Occurrence: dR5P is found in a broad range of organisms, including bacteria and eukaryotes, where conserved enzymatic pathways link the pentose phosphate pathway to the synthesis of DNA precursors. Its specific regulation and routing can vary among species.

See also: pentose phosphate pathway, ribose-5-phosphate, ribonucleotide reductase, deoxyribonucleotide, thymidylate synthase.