Gene Symbol: nrdB
Description: ribonucleoside-diphosphate reductase 1, beta subunit, ferritin-like protein
Alias: ECK2227, JW2229, ftsB
Species: Escherichia coli str. K-12 substr. MG1655
Products:     nrdB

Top Publications

  1. Wu C, Jiang W, Krebs C, Stubbe J. YfaE, a ferredoxin involved in diferric-tyrosyl radical maintenance in Escherichia coli ribonucleotide reductase. Biochemistry. 2007;46:11577-88 pubmed
    ..In 29% of the cases, an open reading frame annotated 2Fe2S ferredoxin (YfaE in Escherichia coli) is located next to nrdB. Thus, YfaE has been cloned, expressed, resolubilized, reconstituted anaerobically with Fe2+, Fe3+, and S2-, and ..
  2. Mitic N, Clay M, Saleh L, Bollinger J, Solomon E. Spectroscopic and electronic structure studies of intermediate X in ribonucleotide reductase R2 and two variants: a description of the FeIV-oxo bond in the FeIII-O-FeIV dimer. J Am Chem Soc. 2007;129:9049-65 pubmed
  3. Fritscher J, Artin E, Wnuk S, Bar G, Robblee J, Kacprzak S, et al. Structure of the nitrogen-centered radical formed during inactivation of E. coli ribonucleotide reductase by 2'-azido-2'-deoxyuridine-5'-diphosphate: trapping of the 3'-ketonucleotide. J Am Chem Soc. 2005;127:7729-38 pubmed
    ..The results are most consistent with the R-S-N*-C-OH structure and provide evidence for the trapping of a 3'-ketonucleotide in the reduction process. ..
  4. Kolberg M, Strand K, Graff P, Andersson K. Structure, function, and mechanism of ribonucleotide reductases. Biochim Biophys Acta. 2004;1699:1-34 pubmed
  5. Stubbe J, Nocera D, Yee C, Chang M. Radical initiation in the class I ribonucleotide reductase: long-range proton-coupled electron transfer?. Chem Rev. 2003;103:2167-201 pubmed
  6. Jacobson B, Fuchs J. A 45 bp inverted repeat is required for cell cycle regulation of the Escherichia coli nrd operon. Mol Microbiol. 1998;28:1307-14 pubmed
    ..The results indicated that the upstream half of the nrd inverted repeat contains a cis-acting element essential for nrd cell cycle regulation. ..
  7. Salowe S, Stubbe J. Cloning, overproduction, and purification of the B2 subunit of ribonucleoside-diphosphate reductase. J Bacteriol. 1986;165:363-6 pubmed
    The nrdB gene, which encodes the B2 subunit of Escherichia coli ribonucleotide reductase (EC, was cloned into multicopy plasmid pSPS2...
  8. Torrents E, Grinberg I, Gorovitz Harris B, Lundström H, Borovok I, Aharonowitz Y, et al. NrdR controls differential expression of the Escherichia coli ribonucleotide reductase genes. J Bacteriol. 2007;189:5012-21 pubmed
    ..The model assumes that differences in the positions of the NrdR binding sites, and in the sequences of the motifs themselves, determine the extent to which NrdR represses the transcription of each RNR operon. ..
  9. Gon S, Camara J, Klungsøyr H, Crooke E, Skarstad K, Beckwith J. A novel regulatory mechanism couples deoxyribonucleotide synthesis and DNA replication in Escherichia coli. EMBO J. 2006;25:1137-47 pubmed
    ..Accordingly, the conversion of ATP-DnaA to ADP-DnaA after initiation and loading of the beta-subunit DnaN would allow increased nrdAB expression, and consequently, coordinated RNR synthesis and DNA replication during the cell cycle. ..

More Information


  1. Kasrayan A, Birgander P, Pappalardo L, Regnstrom K, Westman M, Slaby A, et al. Enhancement by effectors and substrate nucleotides of R1-R2 interactions in Escherichia coli class Ia ribonucleotide reductase. J Biol Chem. 2004;279:31050-7 pubmed
    ..coli class Ia enzyme occurs in a tight 1:1 complex of R1 and R2. Most intriguingly, we also discovered that thioredoxin, one of the physiological reductants of ribonucleotide reductases, enhances the R1-R2 interaction 4-fold. ..
  2. Yee C, Seyedsayamdost M, Chang M, Nocera D, Stubbe J. Generation of the R2 subunit of ribonucleotide reductase by intein chemistry: insertion of 3-nitrotyrosine at residue 356 as a probe of the radical initiation process. Biochemistry. 2003;42:14541-52 pubmed
    ..Under all conditions, the pK(a) was minimally perturbed. This has important mechanistic implications for the radical initiation process. ..
  3. Ge J, Yu G, Ator M, Stubbe J. Pre-steady-state and steady-state kinetic analysis of E. coli class I ribonucleotide reductase. Biochemistry. 2003;42:10071-83 pubmed
  4. Uhlin U, Eklund H. Structure of ribonucleotide reductase protein R1. Nature. 1994;370:533-9 pubmed
    ..The fifth cysteine, in a loop in the centre of the barrel, is positioned to initiate the radical reaction. ..
  5. Filpula D, Fuchs J. Regulation of the synthesis of ribonucleoside diphosphate reductase in Escherichia coli: specific activity of the enzyme in relationship to perturbations of DNA replication. J Bacteriol. 1978;135:429-35 pubmed
    ..Nutritional shifts to faster growth conditions caused cells to transiently overproduce RDP reductase before adjusting to the new steady-state conditions. ..
  6. Stubbe J. Protein structure. Controlling radical reactions. Nature. 1994;370:502 pubmed
  7. Kren B, Fuchs J. Characterization of the ftsB gene as an allele of the nrdB gene in Escherichia coli. J Bacteriol. 1987;169:14-8 pubmed
    ..studies with plasmids and a marker rescue study with bacteriophage M13 nrd indicated that ftsB is an allele of nrdB and that the mutation occurs in the region corresponding to nucleotides 6729 to 7032 of the nrdB gene...
  8. Eliasson R, Reichard P, Mulliez E, Ollagnier S, Fontecave M, Liepinsh E, et al. The mechanism of the anaerobic Escherichia coli ribonucleotide reductase investigated with nuclear magnetic resonance spectroscopy. Biochem Biophys Res Commun. 1995;214:28-35 pubmed
    ..Class I and II enzymes catalyze identical reactions. Members of the three classes of reductases apparently use the same chemical mechanism in spite of having completely different protein structures. ..
  9. Watt R, Wang J, Leong M, Kung H, Cheah K, Liu D, et al. Visualizing the proteome of Escherichia coli: an efficient and versatile method for labeling chromosomal coding DNA sequences (CDSs) with fluorescent protein genes. Nucleic Acids Res. 2007;35:e37 pubmed
    ..Our results show that E. coli has an organized and dynamic proteome, and demonstrate that this approach is applicable for tagging and (co-) localizing CDSs on a genome-wide scale. ..
  10. Casado C, Llagostera M, Barbe J. Expression of nrdA and nrdB genes of Escherichia coli is decreased under anaerobiosis. FEMS Microbiol Lett. 1991;67:153-7 pubmed
    By using plasmid nrdA-lacZ, nrdAB-lacZ, and nrdB-lacZ gene fusions, the expression of nrdA and nrdB genes of Escherichia coli under anaerobiosis has been studied. The results obtained show that cells of E...
  11. Bleifuss G, Kolberg M, Pötsch S, Hofbauer W, Bittl R, Lubitz W, et al. Tryptophan and tyrosine radicals in ribonucleotide reductase: a comparative high-field EPR study at 94 GHz. Biochemistry. 2001;40:15362-8 pubmed
    ..g., DNA photolyase and cytochrome c peroxidase, where they are magnetically coupled to other radicals or to a metal center. ..
  12. Allard P, Kuprin S, Shen B, Ehrenberg A. Binding of the competitive inhibitor dCDP to ribonucleoside-diphosphate reductase from Escherichia coli studied by 1H NMR. Different properties of the large protein subunit and the holoenzyme. Eur J Biochem. 1992;208:635-42 pubmed
    ..5. The effect of R2 without iron (apoR2) is reduced compared with native R2, probably because of some denatured proteins, while a C-terminal peptide from R2 did not cause any narrowing at all. ..
  13. Logan D, deMaré F, Persson B, Slaby A, Sjoberg B, Nordlund P. Crystal structures of two self-hydroxylating ribonucleotide reductase protein R2 mutants: structural basis for the oxygen-insertion step of hydroxylation reactions catalyzed by diiron proteins. Biochemistry. 1998;37:10798-807 pubmed
    ..A critical role for residue Glu238 in directing the oxidative power of the reactive intermediate toward oxidation of Tyr122 is proposed. ..
  14. Coves J, Delon B, Climent I, Sjoberg B, Fontecave M. Enzymic and chemical reduction of the iron center of the Escherichia coli ribonucleotide reductase protein R2. The role of the C-terminus. Eur J Biochem. 1995;233:357-63 pubmed
    ..The properties of the model reaction are described. ..
  15. Hristova D, Wu C, Jiang W, Krebs C, Stubbe J. Importance of the maintenance pathway in the regulation of the activity of Escherichia coli ribonucleotide reductase. Biochemistry. 2008;47:3989-99 pubmed publisher
    ..Whole cell Mössbauer analysis on cells induced with 0.5 mM arabinose supports high iron loading in beta. These results suggest that modulation of the level of Y (*) in vivo in E. coli is a mechanism of regulating RNR activity. ..
  16. Rajagopala S, Hughes K, Uetz P. Benchmarking yeast two-hybrid systems using the interactions of bacterial motility proteins. Proteomics. 2009;9:5296-302 pubmed publisher
  17. Saleh L, Krebs C, Ley B, Naik S, Huynh B, Bollinger J. Use of a chemical trigger for electron transfer to characterize a precursor to cluster X in assembly of the iron-radical cofactor of Escherichia coli ribonucleotide reductase. Biochemistry. 2004;43:5953-64 pubmed
  18. Shanmugam M, Doan P, Lees N, Stubbe J, Hoffman B. Identification of protonated oxygenic ligands of ribonucleotide reductase intermediate X. J Am Chem Soc. 2009;131:3370-6 pubmed publisher
  19. Jacobson B, Fuchs J. Multiple cis-acting sites positively regulate Escherichia coli nrd expression. Mol Microbiol. 1998;28:1315-22 pubmed
  20. Guarino E, Salguero I, Jimenez Sanchez A, Guzmán E. Double-strand break generation under deoxyribonucleotide starvation in Escherichia coli. J Bacteriol. 2007;189:5782-6 pubmed
    ..quot; This reaction occurred at the stalled forks generated by hydroxyurea treatment, was impaired under thermal inactivation of ribonucleoside reductase, and did not take place under thymine starvation. ..
  21. Denysenkov V, Prisner T, Stubbe J, Bennati M. High-field pulsed electron-electron double resonance spectroscopy to determine the orientation of the tyrosyl radicals in ribonucleotide reductase. Proc Natl Acad Sci U S A. 2006;103:13386-90 pubmed
    ..This experiment demonstrates that high-field PELDOR spectroscopy is a powerful tool with which to study the assembly of proteins that contain multiple paramagnetic centers. ..
  22. Zipse H, Artin E, Wnuk S, Lohman G, Martino D, Griffin R, et al. Structure of the nucleotide radical formed during reaction of CDP/TTP with the E441Q-alpha2beta2 of E. coli ribonucleotide reductase. J Am Chem Soc. 2009;131:200-11 pubmed publisher
    ..The results indicate, unexpectedly, that the radical is a semidione nucleotide radical of cytidine 5'-diphosphate. The relationship of this radical to the disulfide radical anion is discussed. ..
  23. Seyedsayamdost M, Xie J, Chan C, Schultz P, Stubbe J. Site-specific insertion of 3-aminotyrosine into subunit alpha2 of E. coli ribonucleotide reductase: direct evidence for involvement of Y730 and Y731 in radical propagation. J Am Chem Soc. 2007;129:15060-71 pubmed
    ..The observed NH2Y. may constitute the first detection of an amino acid radical intermediate in the proposed radical propagation pathway during turnover. ..
  24. Gallardo Madueño R, Leal J, Dorado G, Holmgren A, Lopez Barea J, Pueyo C. In vivo transcription of nrdAB operon and of grxA and fpg genes is triggered in Escherichia coli lacking both thioredoxin and glutaredoxin 1 or thioredoxin and glutathione, respectively. J Biol Chem. 1998;273:18382-8 pubmed compared with the corresponding wild type parent (maximal induction of 10- and 9-fold for mRNA of nrdA and nrdB genes, respectively)...
  25. Seyedsayamdost M, Argirević T, Minnihan E, Stubbe J, Bennati M. Structural examination of the transient 3-aminotyrosyl radical on the PCET pathway of E. coli ribonucleotide reductase by multifrequency EPR spectroscopy. J Am Chem Soc. 2009;131:15729-38 pubmed publisher
    ..This analysis is an essential first step in using the detailed structure of NH(2)Y(730)* to formulate a model for a PCET mechanism within alpha2 and for use of NH(2)Y in other systems where transient Y*s participate in catalysis. ..
  26. Mao S, Yu G, Chalfoun D, Stubbe J. Characterization of C439SR1, a mutant of Escherichia coli ribonucleotide diphosphate reductase: evidence that C439 is a residue essential for nucleotide reduction and C439SR1 is a protein possessing novel thioredoxin-like activity. Biochemistry. 1992;31:9752-9 pubmed
    ..Its additional cysteines, presumably C754 and C759, appear to function as a thioredoxin with the wt-R1, even though it is incapacitated with respect to nucleotide reduction. ..
  27. Herrick J, Sclavi B. Ribonucleotide reductase and the regulation of DNA replication: an old story and an ancient heritage. Mol Microbiol. 2007;63:22-34 pubmed
    ..In this review we examine the role RNR plays in regulating the total rate of DNA synthesis in E. coli and, hence, in maintaining constant DNA/cell mass ratios during normal growth and under conditions of DNA stress. ..
  28. Tong W, Burdi D, Riggs Gelasco P, Chen S, Edmondson D, Huynh B, et al. Characterization of Y122F R2 of Escherichia coli ribonucleotide reductase by time-resolved physical biochemical methods and X-ray crystallography. Biochemistry. 1998;37:5840-8 pubmed
    ..Studies with two mutants, Y356F and double mutant Y356F and Y122F R2, are interpreted in terms of the possible role of Y356 in the putative electron transfer reaction between the R1 and R2 subunits of this RNR. ..
  29. Eriksson M, Uhlin U, Ramaswamy S, Ekberg M, Regnstrom K, Sjoberg B, et al. Binding of allosteric effectors to ribonucleotide reductase protein R1: reduction of active-site cysteines promotes substrate binding. Structure. 1997;5:1077-92 pubmed
    ..The general allosteric effector site, located far from the active site, appears to regulate subunit interactions within the holoenzyme. ..
  30. Seyedsayamdost M, Yee C, Stubbe J. Site-specific incorporation of fluorotyrosines into the R2 subunit of E. coli ribonucleotide reductase by expressed protein ligation. Nat Protoc. 2007;2:1225-35 pubmed
    ..Ligation of the 22-mer peptide to the thioester-activated R2 and subsequent purification yield full-length R2 with the F(n)Y at residue 356. The procedure to generate 100 mg quantities of Y356F(n)Y-R2 takes 3-4 months. ..
  31. Taschner P, Verest J, Woldringh C. Genetic and morphological characterization of ftsB and nrdB mutants of Escherichia coli. J Bacteriol. 1987;169:19-25 pubmed
    The ftsB gene of Escherichia coli is believed to be involved in cell division. In this report, we show that plasmids containing the nrdB gene could complement the ftsB mutation, suggesting that ftsB is an allele of nrdB...
  32. Nordlund P, Sjoberg B, Eklund H. Three-dimensional structure of the free radical protein of ribonucleotide reductase. Nature. 1990;345:593-8 pubmed
    ..Tyrosine 122, which harbours the stable free radical necessary for the activity of ribonucleotide reductase, is buried inside the protein and is located 5 A from the closest iron atom. ..
  33. Yamada M, Takeda Y, Okamoto K, Hirota Y. Physical map of the nrdA-nrdB-ftsB-glpT region of the chromosomal DNA of Escherichia coli. Gene. 1982;18:309-18 pubmed
    Seven pLC plasmids (pLC 3-46, 8-12, 8-24, 8-29, 14-12, 19-24 and 42-17) which complemented nrdA, nrdB, ftsB and/or glpT mutations of Escherichia coli were analyzed...
  34. Reece S, Seyedsayamdost M, Stubbe J, Nocera D. Electron transfer reactions of fluorotyrosyl radicals. J Am Chem Soc. 2006;128:13654-5 pubmed
    ..These data demonstrate that fluorotyrosines will be powerful probes for unraveling charge transport mechanisms in enzymes that utilize tyrosyl radicals. ..
  35. Ahluwalia D, Bienstock R, Schaaper R. Novel mutator mutants of E. coli nrdAB ribonucleotide reductase: insight into allosteric regulation and control of mutation rates. DNA Repair (Amst). 2012;11:480-7 pubmed publisher
    ..These mutants provide new insight into the precise mechanisms by which RNR is regulated and how dNTP pool disturbances resulting from defects in RNR can lead to increased mutation. ..
  36. Reece S, Seyedsayamdost M, Stubbe J, Nocera D. Photoactive peptides for light-initiated tyrosyl radical generation and transport into ribonucleotide reductase. J Am Chem Soc. 2007;129:8500-9 pubmed
  37. Ekberg M, Sahlin M, Eriksson M, Sjoberg B. Two conserved tyrosine residues in protein R1 participate in an intermolecular electron transfer in ribonucleotide reductase. J Biol Chem. 1996;271:20655-9 pubmed
    ..It is demonstrated that there is no electron delocalization over these tyrosines in the resting wild-type complex. ..
  38. Jordan A, Aragall E, Gibert I, Barbe J. Promoter identification and expression analysis of Salmonella typhimurium and Escherichia coli nrdEF operons encoding one of two class I ribonucleotide reductases present in both bacteria. Mol Microbiol. 1996;19:777-90 pubmed
    ..In contrast to the nrdAB genes, the nrdEF operon is not essential to the cells because nrdEF-defective mutants are viable under both aerobic and anaerobic conditions. ..
  39. Garriga X, Eliasson R, Torrents E, Jordan A, Barbe J, Gibert I, et al. nrdD and nrdG genes are essential for strict anaerobic growth of Escherichia coli. Biochem Biophys Res Commun. 1996;229:189-92 pubmed
    ..Interestingly, these mutants grow well under microaerophilic conditions by overproducing the aerobic enzyme. Under such conditions wild-type bacteria turn off nrdAB and switch on nrdDG. ..
  40. Salowe S, Ator M, Stubbe J. Products of the inactivation of ribonucleoside diphosphate reductase from Escherichia coli with 2'-azido-2'-deoxyuridine 5'-diphosphate. Biochemistry. 1987;26:3408-16 pubmed
    ..Incubation of [5'-3H]N3UDP with RDPR resulted in stoichiometric covalent radiolabeling of the enzyme. Separation of the enzyme's subunits by chromatofocusing revealed that the modification was specific for the B1 subunit. ..
  41. Platz A, Sjoberg B. Construction and characterization of hybrid plasmids containing the Escherichia coli nrd region. J Bacteriol. 1980;143:561-8 pubmed
    ..This establishes that in E. coli the inhibition of deoxyribonucleic acid synthesis by hydroxyurea is fully explained by its action on ribonucleotide reductase. ..
  42. Filpula D, Fuchs J. Regulation of ribonucleoside diphosphate reductase synthesis in Escherichia coli: increased enzyme synthesis as a result of inhibition of deoxyribonucleic acid synthesis. J Bacteriol. 1977;130:107-13 pubmed
  43. Gon S, Faulkner M, Beckwith J. In vivo requirement for glutaredoxins and thioredoxins in the reduction of the ribonucleotide reductases of Escherichia coli. Antioxid Redox Signal. 2006;8:735-42 pubmed
    ..These findings indicate a role for these enzymes either for NrdDG reactivation or some other essential anaerobic process. ..
  44. Seyedsayamdost M, Yee C, Reece S, Nocera D, Stubbe J. pH Rate profiles of FnY356-R2s (n = 2, 3, 4) in Escherichia coli ribonucleotide reductase: evidence that Y356 is a redox-active amino acid along the radical propagation pathway. J Am Chem Soc. 2006;128:1562-8 pubmed
  45. Sommerhalter M, Saleh L, Bollinger J, Rosenzweig A. Structure of Escherichia coli ribonucleotide reductase R2 in space group P6122. Acta Crystallogr D Biol Crystallogr. 2005;61:1649-54 pubmed
    ..6 Angstroms resolution by molecular replacement. The crystallization conditions, backbone conformation, crystal-packing interactions and metal centers are compared with those of previously determined crystal forms. ..
  46. Climent I, Sjoberg B, Huang C. Site-directed mutagenesis and deletion of the carboxyl terminus of Escherichia coli ribonucleotide reductase protein R2. Effects on catalytic activity and subunit interaction. Biochemistry. 1992;31:4801-7 pubmed
    ..While E350A protein exhibits a low (240 times less active than the wild-type) but definitive activity, Y356A is completely inactive. A catalytic rather than structural role for these residues is discussed. ..
  47. Granston A, Thompson D, Friedman D. Identification of a second promoter for the metY-nusA-infB operon of Escherichia coli. J Bacteriol. 1990;172:2336-42 pubmed
    ..We demonstrate that P-1 is active in vivo. ..
  48. Saleh L, Kelch B, Pathickal B, Baldwin J, Ley B, Bollinger J. Mediation by indole analogues of electron transfer during oxygen activation in variants of Escherichia coli ribonucleotide reductase R2 lacking the electron-shuttling tryptophan 48. Biochemistry. 2004;43:5943-52 pubmed
    ..2-fold to a final value of 0.75 equiv and suppressing formation of a 490 nm absorbing product that results from decay of the two-electron oxidized intermediate in the absence of a functional ET apparatus. ..
  49. Hassan A, Wang Y, Plate L, Stubbe J. Methodology to probe subunit interactions in ribonucleotide reductases. Biochemistry. 2008;47:13046-55 pubmed publisher
    ..4 microM for subunit interaction. Disruption of the interaction of the alpha2-DAN-beta2 complex is accompanied by a decrease in fluorescence intensity and can serve as a high-throughput screen for inhibitors of subunit interactions. ..
  50. Carlson J, Fuchs J, Messing J. Primary structure of the Escherichia coli ribonucleoside diphosphate reductase operon. Proc Natl Acad Sci U S A. 1984;81:4294-7 pubmed
    ..6012 and 7139, encoding a 375-amino acid polypeptide with a molecular weight of 43,466, has been identified as the nrdB gene...
  51. Artin E, Wang J, Lohman G, Yokoyama K, Yu G, Griffin R, et al. Insight into the mechanism of inactivation of ribonucleotide reductase by gemcitabine 5'-diphosphate in the presence or absence of reductant. Biochemistry. 2009;48:11622-9 pubmed publisher
    ..The EPR features are very similar to those we recently reported for the nucleotide radical generated with CDP and E441Q-RNR. ..
  52. Thelander L, Sjöberg B, Eriksson S. Ribonucleoside diphosphate reductase (Escherichia coli). Methods Enzymol. 1978;51:227-37 pubmed
  53. Smith S, Douglas K. Stereoselective, strong inhibition of ribonucleotide reductase from E. coli by cisplatin. Biochem Biophys Res Commun. 1989;162:715-23 pubmed
    ..3) led to a decrease in thiol titre corresponding to approximately 1 thiol group per dimer of B1 subunits under conditions leading to 94% inactivation of the ribonucleotide reductase activity. ..
  54. Waldman H. Baby fat is cute, but chubby kids may be in danger. ASDC J Dent Child. 2000;67:15-7, 8 pubmed
    ..An increasing percent of children are overweight. A review of the prevalence of overweight children in different demographic groups is provided in an effort to alert dentists to the role they could play in preventing medical complications. ..
  55. Brown N, Reichard P. Ribonucleoside diphosphate reductase. Formation of active and inactive complexes of proteins B1 and B2. J Mol Biol. 1969;46:25-38 pubmed
  56. Pierce B, Elgren T, Hendrich M. Mechanistic implications for the formation of the diiron cluster in ribonucleotide reductase provided by quantitative EPR spectroscopy. J Am Chem Soc. 2003;125:8748-59 pubmed
    ..This work represents the first instance where both X- and Q-band simulations of perpendicular and parallel mode spectra were used to quantitatively predict the concentration of a protein bound mononuclear Mn(II) species. ..
  57. Larsson A, Climent I, Nordlund P, Sahlin M, Sjoberg B. Structural and functional characterization of two mutated R2 proteins of Escherichia coli ribonucleotide reductase. Eur J Biochem. 1996;237:58-63 pubmed
    ..Two randomly generated genomic mutants, nrdB-1 and nrdB-2, that produce R2 enzymes with low enzymatic activity, have been cloned and characterized to identify ..
  58. Logan D, Su X, Aberg A, Regnstrom K, Hajdu J, Eklund H, et al. Crystal structure of reduced protein R2 of ribonucleotide reductase: the structural basis for oxygen activation at a dinuclear iron site. Structure. 1996;4:1053-64 pubmed
    ..The Ser211--> Ala mutant displays a conformational change in the helix containing the mutation, explaining its altered reduction kinetics. ..
  59. Brown N, Canellakis Z, Lundin B, Reichard P, Thelander L. Ribonucleoside diphosphate reductase. Purification of the two subunits, proteins B1 and B2. Eur J Biochem. 1969;9:561-73 pubmed
  60. Ekberg M, Pötsch S, Sandin E, Thunnissen M, Nordlund P, Sahlin M, et al. Preserved catalytic activity in an engineered ribonucleotide reductase R2 protein with a nonphysiological radical transfer pathway. The importance of hydrogen bond connections between the participating residues. J Biol Chem. 1998;273:21003-8 pubmed
    ..Our data thus strongly favor the idea that the electron transfer mechanism in RNR is coupled with proton transfer, i.e. a radical transfer mechanism. ..
  61. Saleh L, Bollinger J. Cation mediation of radical transfer between Trp48 and Tyr356 during O2 activation by protein R2 of Escherichia coli ribonucleotide reductase: relevance to R1-R2 radical transfer in nucleotide reduction?. Biochemistry. 2006;45:8823-30 pubmed
    ..Possible mechanisms of this cation mediation and its potential relevance to intersubunit radical transfer during nucleotide reduction are considered. ..
  62. Seyedsayamdost M, Stubbe J. Site-specific replacement of Y356 with 3,4-dihydroxyphenylalanine in the beta2 subunit of E. coli ribonucleotide reductase. J Am Chem Soc. 2006;128:2522-3 pubmed
    ..They further show that substrate binding brings about rapid conformational changes which place the complex into its active form(s) and suggest that the RNR complex is asymmetric. ..
  63. Lu S, Libby E, Saleh L, Xing G, Bollinger J, Moenne Loccoz P. Characterization of NO adducts of the diiron center in protein R2 of Escherichia coli ribonucleotide reductase and site-directed variants; implications for the O2 activation mechanism. J Biol Inorg Chem. 2004;9:818-27 pubmed
    ..The formation of equivalent NO adducts in the wt and variant proteins strongly favors the formation of a symmetric bridging peroxo intermediate during the O(2) activation process in R2-wt. ..
  64. Thelander L. Physicochemical characterization of ribonucleoside diphosphate reductase from Escherichia coli. J Biol Chem. 1973;248:4591-601 pubmed
  65. Odsbu I, Morigen -, Skarstad K. A reduction in ribonucleotide reductase activity slows down the chromosome replication fork but does not change its localization. PLoS ONE. 2009;4:e7617 pubmed publisher
    ..Control of cell division but not control of initiation was affected by the changes in replication elongation. ..
  66. Pierce B, Hendrich M. Local and global effects of metal binding within the small subunit of ribonucleotide reductase. J Am Chem Soc. 2005;127:3613-23 pubmed
    ..The mixed metal FeMn species are quantitatively characterized with electron paramagnetic resonance spectroscopy. The previously reported catalase activity of Mn2(II)R2 is shown not to be associated with Mn. ..
  67. Rofougaran R, Crona M, Vodnala M, Sjoberg B, Hofer A. Oligomerization status directs overall activity regulation of the Escherichia coli class Ia ribonucleotide reductase. J Biol Chem. 2008;283:35310-8 pubmed publisher
    ..The E. coli RNR differs from the mammalian enzyme, which is stimulated by ATP also in combination with dGTP/dTTP and forms active and inactive alpha(6)beta(2) complexes. ..
  68. Bollinger J. Biochemistry. Electron relay in proteins. Science. 2008;320:1730-1 pubmed publisher
  69. Reichard P. Enzymatic synthesis of deoxyribonucleotides. I. Formation of deoxycytidine diphosphate from cytidine diphosphate with enzymes from Escherichia coli. J Biol Chem. 1962;237:3513-9 pubmed
  70. Reece S, Seyedsayamdost M, Stubbe J, Nocera D. Direct observation of a transient tyrosine radical competent for initiating turnover in a photochemical ribonucleotide reductase. J Am Chem Soc. 2007;129:13828-30 pubmed
  71. Högbom M, Andersson M, Nordlund P. Crystal structures of oxidized dinuclear manganese centres in Mn-substituted class I ribonucleotide reductase from Escherichia coli: carboxylate shifts with implications for O2 activation and radical generation. J Biol Inorg Chem. 2001;6:315-23 pubmed
    ..Probable catalase activity was also observed during the oxidation with H2O2, indicating mechanistic similarities to the di-Mn catalases. ..
  72. Han J, Kwon H, Yim J, Hwang D. Effect of IciA protein on the expression of the nrd gene encoding ribonucleoside diphosphate reductase in E. coli. Mol Gen Genet. 1998;259:610-4 pubmed
    ..In vivo overexpression of IciA increases the expression of nrd gene by four- to five-fold, suggesting that IciA functions as a transcriptional activator for the nrd gene. ..
  73. Hanke P, Fuchs J. Regulation of ribonucleoside diphosphate reductase mRNA synthesis in Escherichia coli. J Bacteriol. 1983;154:1040-5 pubmed
  74. Sun L, Fuchs J. Escherichia coli ribonucleotide reductase expression is cell cycle regulated. Mol Biol Cell. 1992;3:1095-105 pubmed
    ..When nrd sequences surrounding the promoter were removed from this construct, lac-mRNA and beta-galactosidase synthesis were no longer cell cycle regulated. ..
  75. Seyedsayamdost M, Reece S, Nocera D, Stubbe J. Mono-, di-, tri-, and tetra-substituted fluorotyrosines: new probes for enzymes that use tyrosyl radicals in catalysis. J Am Chem Soc. 2006;128:1569-79 pubmed
  76. Minnihan E, Seyedsayamdost M, Stubbe J. Use of 3-aminotyrosine to examine the pathway dependence of radical propagation in Escherichia coli ribonucleotide reductase. Biochemistry. 2009;48:12125-32 pubmed publisher
    ..2-0.3% of that observed at 731 and 730, and with (c), no NH(2)Y(*) was observed. These studies suggest the evolution of an optimized pathway of conserved Ys in the oxidation of C(439). ..
  77. Tuggle C, Fuchs J. Regulation of the operon encoding ribonucleotide reductase: role of the negative sites in nrd repression. J Bacteriol. 1990;172:1711-8 pubmed