Ribonucleotide reductase M2 subunit is one of two subunits that constitute ribonucleotide reductase, the enzyme that catalyzes the conversion of ribonucleotide 5'-diphosphates into 2'-deoxyribonucleotides, a rate-limiting step in the production of 2'-deoxyribonucleoside 5'-diphosphates (dNTP) required for DNA synthesis and repair that is required for DNA synthesis and repair . RRM2 is only expressed during the late G1/early S phase, and degraded in late S phase, and the activity of RNR, and therefore DNA synthesis and cell proliferation, is controlled during the cell cycle by the synthesis and degradation of RRM2 subunit.
