Two steps from CDP: ribonucleotide reductase removes the 2' hydroxyl, then a kinase adds a phosphate
Route: Cytidine diphosphate → Deoxycytidine diphosphate → Deoxycytidine triphosphate
Ribonucleotide reductase turns CDP into dCDP by removing the 2' hydroxyl of the ribose, with electrons that reach the enzyme from NADPH through thioredoxin. dATP at the regulatory site of the enzyme directs it to CDP and UDP. Nucleoside diphosphate kinase then moves a phosphate from ATP to dCDP and gives dCTP. CDP itself is not made by a pathway on this site. Cells get it from CMP by UMP/CMP kinase, and the CTP pathway shows the matching step for UMP. The other pyrimidine deoxynucleotide, dTMP, has its own pathway that also starts with ribonucleotide reductase.
Practice this pathway All pathways
| Step | Enzyme | EC | In | Out |
|---|---|---|---|---|
| 1 | Ribonucleotide reductase | 1.17.4.1 | Trx-(SH)₂ | Trx-S₂, H₂O |
| 2 | Nucleoside diphosphate kinase | 2.7.4.6 | ATP | ADP |
Enzyme names and EC numbers are those used on the interactive board. Checked against sources: see the claim table in the repository (tools/pathway_data/checks).