<p> Proteins in this entry represent a small clade of ribonucleoside-diphosphate reductase alpha chains which are sufficiently divergent from the usual Class I ribonucleotide reductase (RNR) alpha chains (NrdE or NrdA, <db_xref db="INTERPRO" dbkey="IPR013346"/>) to form a distinct group. The genes from <taxon tax_id="274">Thermus thermophilus</taxon>, Dichelobacter and Salinibacter are adjacent to the usual RNR beta chain.</p> Ribonucleoside-diphosphate reductase alpha chain