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MS
rate-limiting unreviewed

Ribonucleotide reductase (RNR, class Ia)

1 reactions · 1 pathways

Clinical / pharmacological. Target of hydroxyurea; allosterically controlled by dNTPs

What it does, reaction by reaction

1 reactions

Deoxyribonucleotide Formation (Ribonucleotide Reductase pathway and thymidylate synthesis) Nucleotide Metabolism · Cytosol

step 1 Irreversible/directional rate-limiting

Nucleoside diphosphates → deoxyribonucleoside diphosphates

Converts ADP GDP CDP UDP into dADP dGDP dCDP dUDP

Notes

Class Ia RNR catalyzes ADP, GDP, CDP, or UDP + reducing equivalents → dADP, dGDP, dCDP, or dUDP + oxidized electron-transfer proteins. The human enzyme is an alpha2beta2 complex: the RRM2/RRM2B small subunit uses a diiron center to generate a stable tyrosyl radical, and the RRM1 large subunit contains catalytic cysteines that reduce the 2′-hydroxyl group. Reducing equivalents are transferred from NADPH through thioredoxin reductase and reduced thioredoxin (or through NADPH, glutathione reductase, glutathione, and glutaredoxin); the chemical reduction of each NDP requires one NADPH-derived pair of electrons. This is the rate-limiting and committed step for de novo deoxyribonucleotide production.

Showing all 1 reactions.

What accelerates and inhibits it

Regulation is pathway-specific, so each context is listed separately

0 entries

No regulation recorded for this enzyme in the source documents.

Recent literature

Europe PMC · from cache · sorted by publication date

  1. 1
    Mechanistic studies on HNRNPA2B1 suggest binding but not selective recognition of m<sup>6</sup>A.

    Park R, Demny M, Miller LG, Pedraza C, Xenophontos X, Hunt RK, Orr AA, Perez LM, Montalbano M, Contreras LM, … · 2026-03-02

    cited 1× open access unreviewed
  2. 2
    Ensemble Docking and Molecular Dynamics Indicate Dynamic Modulation of hnRNPA1 UP1 Interdomain Behavior by Natural Products.

    Lourembam RM, Raj N, Sharma GS, Sarangthem ID, Sharma NH, Thorat SS. · 2026-07-02

    unreviewed
  3. 3
    HuR-HuB autoregulatory network governs inflammatory factors expression.

    Fu X, Lu Y, Kong L, Qi Y, Zhong X, Ba X, Ke Y. · 2026-05-20

    open access unreviewed
  4. 4
    Adaptive Regulation of dNTP Homeostasis Confers Osimertinib Resistance in EGFR-Mutant Non-Small Cell Lung Carcinoma.

    Xie Q, Wang Y, Fernandez A, Lei Y, Gong Y, Hess JD, Yang L, Xin D, Williams TM, Zheng L, Shen B, Li M. · 2026-07-01

    open access unreviewed
  5. 5
    A resource of RNA-binding protein motifs across eukaryotes reveals evolutionary dynamics and gene-regulatory function.

    Sasse A, Ray D, Laverty KU, Tam CL, Albu M, Zheng H, Levdansky Y, Lyudovyk O, Dalal T, Nie K, Magis C, Notred… · 2025-07-25

    cited 16× unreviewed
  6. 6
    A mechanism of target mRNA selection and activity regulation in meiosis-related RBM46-MEIOC-YTHDC2 complex.

    Liang R, Chen Q, Li J, Liu H, Ma Y, Han S, Li Y, Gao J, Ye L, Zhou J. · 2026-06-03

    open access unreviewed
  7. 7
    HIV-1 signalling remodels nuclear pores to licence infection.

    Mesner D, Whelan MVX, Shivkumar M, Reuschl AK, Chiozzi RZ, Thalassinos K, de Bruin RAM, Jolly C. · 2026-05-06

    cited 1× open access unreviewed
  8. 8
  9. 9
    A Nanos3-containing protein complex can activate RNA translation in primordial germ cells in vivo.

    Gupta A, Basaran AM, Ophaus M, Madiwale S, Stehling M, Reichman-Fried M, Tarbashevich K, Raz E. · 2026-04-24

    cited 1× open access unreviewed
  10. 10
    Ligand-specific conformational dynamics and interaction landscapes of hnRNPA2B1 reveal a structural basis for its functional regulation.

    Zhou Z, Li Y, Yang P, Zhu R, Li J, Wu B, Xu M, Yang N, Dai S. · 2026-03-03

    open access unreviewed

External claims. These come from an index outside this database and are not checked against it. Treat them as leads.