1.17.4.2 dimer - 437893 1.17.4.2 dimer both subunits are required for catalytic activity 715583 1.17.4.2 monomer - 437889, 437892, 437893, 437895, 437896 1.17.4.2 monomer 1 * 50000, SDS-PAGE -, 437893 1.17.4.2 monomer 1 * 76000 714186 1.17.4.2 monomer 1 * 78400, SDS-PAGE 437890 1.17.4.2 monomer or dimer alpha or alpha2, class II RNRs 715085 1.17.4.2 monomer or dimer class II enzymes show a monomeric or dimeric structure 716317 1.17.4.2 additional information structure comparisons of classI-III RNRs, model for the subunit organization of RNRs, overview 715085 1.17.4.2 additional information structures of the active holoenzymes of class I-III RNRs, structure comparisons, overview 716317 1.17.4.2 additional information the enzyme is encoded by two consecutive open reading frames denated nrdJa and nrdJb and separated by 16 bp. The presence of both NrdJa and NrdJb subunits is absolutely essential for enzyme activity 659464 1.17.4.2 tetramer 2 * M1-subunit + 2 * M2-subunit 688754 1.17.4.2 tetramer 4 * 100000, SDS-PAGE -, 437891 1.17.4.2 tetramer alpha2beta2 heterodimer with a regulatory, nucleotide binding site M1 subunit, and an inducible, catalytic M2 subunit which contains non-heme iron and a tyrosyl free radical, that are required for the enzymatic reduction of ribonucleotides 688750 1.17.4.2 tetramer alpha2beta2, class III RNRs 715085 1.17.4.2 tetramer RNR is a tetramer consisting of two non-identical homodimers. The two identical M2 subunits regulate the substrate specificity of the enzyme, while the other two identical M1 subunits are responsible for the activity by binding the ribonucleotides and allosteric effectors 685023