Ribonucleotide Reductase M2 (RRM2)

RRM2 encodes one of two non-identical subunits for ribonucleotide reductase. This reductase catalyzes the formation of deoxyribonucleotides from ribonucleotides. Synthesis of the encoded protein (M2) is regulated in a cell-cycle dependent fashion. Transcription from this gene can initiate from alternative promoters, which results in two isoforms that differ in the lengths of their N-termini. Related pseudogenes have been identified on chromosomes 1 and X.The deduced 389-amino acid RRM2 protein has a molecular mass of 45 kD and is 1 amino acid shorter than the equivalent mouse protein. The human and mouse RRM2 proteins share 96% homology in the C terminus, but only 69% in the first 68 residues in the N terminus.