Predicted to enable identical protein binding activity and ribonucleoside-diphosphate reductase activity, thioredoxin disulfide as acceptor. Involved in response to amine. Predicted to be located in nucleoplasm. Predicted to be active in cytosol. Human ortholog(s) of this gene implicated in autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions 5; mitochondrial DNA depletion syndrome 8a; and mitochondrial DNA depletion syndrome 8b. Orthologous to human RRM2B (ribonucleotide reductase regulatory TP53 inducible subunit M2B). [provided by Alliance of Genome Resources, Apr 2022]