Biochemistry · Molecule
dTMP (thymidine monophosphate) !
dTMP is the thymine nucleotide, unique to DNA; many cancer drugs work by preventing its formation.
Updated 2026-11-01
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Key facts
- Thymidylate synthase makes it by methylating dUMP with N⁵,N¹⁰-methylene-THF, which is left as DHF.
- DHFR regenerates THF: that is why methotrexate (DHFR) and 5-FU (thymidylate synthase) stop DNA synthesis.
- Thymine is uracil with a methyl at C5; DNA uses thymine so that uracil arising from damage can be recognised.
- It also forms by salvage: thymidine kinase + thymidine → dTMP.
- Also called
- Thymidylic acid
- Formula
- C₁₀H₁₅N₂O₈P
- PubChem
- CID 9700
Structure
- Thymine linked to a 2'-deoxyribose with a phosphate on C5'.
- It is phosphorylated to dTDP and dTTP before entering DNA.
Clinical notes
- Without dTMP dividing cells die («thymineless death»): the basis of 5-FU, capecitabine and methotrexate.
- Folate or B12 deficiency slows its synthesis and produces megaloblastic anaemia.
Pathways
Related conditions
Related
- Thymidylate synthase
- Dihydrofolate reductase (DHFR)
- Ribonucleotide reductase
- Drugs acting on nucleotide metabolism
- Nucleotide structure
Test yourself
Think of the answer, then tap the question to see it.
From which molecule is dTMP made?
From dUMP, by methylation by thymidylate synthase.
Why does methotrexate stop dTMP formation?
It blocks DHFR; without regenerated THF there is no methylene-THF for thymidylate synthase.
What is the chemical difference between thymine and uracil?
Thymine has a methyl group at C5 of the ring.
Molecules are shown in their neutral form, as the databases deposit them; in the cell the acids and phosphates are ionised.
Educational information, not medical advice. For any symptom, see a health professional.
Sources: 5'-Thymidylic acid (CID 9700) (PubChem, NCBI, 2026) · Public domain; Interconversion of nucleotide di- and triphosphates (Reactome, 2026); TYMS: Thymidylate synthase (human) (UniProt, 2026).
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