v5.1.0.3
Glycine data from LIS
Type | Family |
Description | Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase, ( ) [ , ] catalyses the reductive synthesisof deoxyribonucleotides from their corresponding ribonucleotides: 2'-deoxyribonucleoside diphosphate + oxidized thioredoxin + H2O = ribonucleoside diphosphate + reduced thioredoxin RNR provides the precursors necessary for DNA synthesis. RNRs divide into three classes on the basis of their metallocofactor usage. Class I RNRs, found in eukaryotes, bacteria, bacteriophage and viruses, use a diiron-tyrosyl radical, Class II RNRs, found in bacteria,bacteriophage, algae and archaea, use coenzyme B12 (adenosylcobalamin, AdoCbl). Class III RNRs, found inanaerobic bacteria and bacteriophage, use an FeS cluster and S-adenosylmethionine to generate a glycyl radical. Manyorganisms have more than one class of RNR present in their genomes. Class I ribonucleotide reductase is an oligomeric enzyme composed of a large subunit (700 to 1000 residues) and a small subunit (300 to 400 residues) - class II RNRs are less complex, using the small molecule B12 in place of the small chain [ ]. The small chain binds two iron atoms [] (three Glu, one Asp, and two His areinvolved in metal binding) and contains an active site tyrosine radical. The regions of the sequence that contain the metal-binding residues and the activesite tyrosine are conserved in ribonucleotide reductase small chain from prokaryotes, eukaryotes and viruses.This family consist of the small subunit of class I ribonucleotide reductases. It also includes R2-like ligand-binding oxidase, which is homologous to the ribonucleotide reductase small subunit (R2), but whose function is still unknown [ , ]. |
Short Name | RNR_small_fam |