ribonucleoside-diphosphate reductase subunit M2 B; TP53-inducible ribonucleotide reductase M2 B; p53-inducible ribonucleotide reductase small subunit 2-like protein; p53R2 (RRM2B, P53R2)

Function

• role in cell survival by repairing damaged DNA (p53-dependent)
• supplies deoxyribonucleotides for DNA repair in cells arrested at G1 or G2
• forms an active ribonucleotide reductase (RNR) complex with RRM1 which is expressed both in resting & proliferating cells in response to DNA damage
• interacts with p53/TP53
• interacts with RRM1 in response to DNA damage
• genetic information processing; DNA replication

2'-deoxyribonucleoside diphosphate + thioredoxin disulfide + H2O
          <-->
ribonucleoside diphosphate + thioredoxin

Cofactor: binds 2 iron ions per subunit (putative)

Structure

• heterotetramer with large (RRM1) subunit
• contains an iron-tyrosyl free radical center required for catalysis
• belongs to the ribonucleoside diphosphate reductase small chain family

Compartment

• cytoplasm, nucleus
• translocates from cytoplasm to nucleus in response to DNA damage

Alternative splicing

named isoforms=5

Expression

• widely expressed
• high level in skeletal muscle
• weak level in thymus
• expressed in response to DNA damage (p53-dependent)

Pathology

• defects in RRM2B are the cause of encephalomyopathic mitochondrial depletion syndrome with renal tubulopathy
• expressed in epithelial dysplasias & squamous cell carcinoma

More general terms

• oxidoreductase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=50484
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:50484
• OMIM: https://mirror.omim.org/entry/604712
• OMIM: https://mirror.omim.org/entry/612075
• UniProt: http://www.uniprot.org/uniprot/Q7LG56.html