Ribonucleotide reductase R2 subunit mRNA (RRM2 mRNA)

The **ribonucleotide reductase R2 subunit mRNA** encodes the R2 (small or β) subunit of ribonucleotide reductase, an essential, highly conserved enzyme that catalyzes the reduction of ribonucleotides to deoxyribonucleotides, thereby supplying the building blocks for DNA synthesis and repair[4][3]. The **R2 subunit** provides a stable tyrosyl radical (Y•) within a di-iron or other metal cofactor center, which is essential for the radical-based reduction chemistry catalyzed by the enzyme[2][7]. The R2 subunit forms a complex with the R1 (large or α) subunit; long-range radical transfer between these subunits is required for enzymatic function. Expression of RRM2 (the gene encoding the R2 subunit) is tightly regulated during the cell cycle, peaking in S-phase[3]. Overexpression of RRM2 is associated with cancer cell proliferation and genomic instability, making RRM2 a validated therapeutic target for oncology and a marker for S-phase and proliferative activity[3][4][6]. Pharmacological inhibition of the R2 subunit or its mRNA (via RNAi or small molecules like hydroxyurea or triapine) impairs DNA synthesis and has been developed for cancer and antiviral therapies[6][5]. **Clarification:** - The queried entity “R2 subunit mRNA of ribonucleotide reductase” is *not* the actual protein target but rather the messenger RNA encoding it. RRM2 mRNA is used as a biomarker and as a target for RNA interference strategies, but the canonical therapeutic target is the R2 protein subunit itself. Thus, this entry is technically incorrect as a direct target, but can still be referenced for biomarker or molecular biology applications[3][4]. - For most drug targeting and pharmacological purposes, the correct canonical target is "Ribonucleotide reductase R2 subunit" (protein), encoded by the RRM2 gene. - If you need strictly the *protein* target for structured data, use "Ribonucleotide reductase small subunit (R2 or RRM2)." **Summary of key points:** - **R2 subunit** is the radical-generating component of ribonucleotide reductase, essential for DNA synthesis[2][4]. - **RRM2 mRNA** levels are regulated through the cell cycle and can be aberrant in cancer[3]. - **Therapeutic targeting** focuses on blocking R2 protein activity, but mRNA level can be exploited for diagnosis or RNA-targeting intervention. - **This is not a canonical drug target name (protein level is preferred for drug discovery/treatment references)**[3][4].

Other names

R2 subunit of ribonucleotide reductaseribonucleotide reductase small subunitRRM2 mRNAribonucleotide reductase M2 mRNAribonucleoside-diphosphate reductase subunit M2 mRNA

Inhibition of radical formation or activity (by hydroxyurea, triapine), inhibition of ribonucleotide reduction (by nucleoside analogs like gemcitabine), iron chelation (by gallium compounds)