Ribonucleotide reductase, class I , alpha subunit (IPR013346)

Short name: NrdE_NrdA

Overlapping homologous superfamilies


Domain relationships


This entry represents the alpha (large) chain of the class I ribonucleotide reductase (RNR). RNR's are responsible for the conversion of the ribose sugar of RNA into the deoxyribose sugar of DNA. This is the rate-limiting step of DNA biosynthesis. Class I RNR's generate the required radical (on tyrosine) via a "non-heme" iron cofactor which resides in the beta (small) subunit. The alpha subunit contains the catalytic and allosteric regulatory sites. The mechanism of this enzyme requires molecular oxygen [PMID: 11807048]. Escherichia coli contains two versions of this enzyme which are regulated independently (NrdAB and NrdEF, where NrdA and NrdE are the large chains [PMID: 8052308, PMID: 8820648]). Most organisms contain only one, but the application of the gene symbols NrdA and NrdE are somewhat arbitrary. This model identifies RNR's in diverse clades of bacteria, eukaryotes as well as numerous DNA viruses and phage.

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.