A new class EC 7, Translocases, has been added to the EC list. It will be part of ENZYME from release 2018_10. Read more about EC 7 here.

ENZYME entry: EC 1.17.4.1

Accepted Name
Ribonucleoside-diphosphate reductase.
Alternative Name(s)
Ribonucleotide reductase.
Reaction catalysed
2'-deoxyribonucleoside diphosphate + thioredoxin disulfide + H(2)O <=> ribonucleoside diphosphate + thioredoxin
Cofactor(s)
Fe(3+) or adenosylcob(III)alamin or Mn(2+).
Comment(s)
  • This enzyme is responsible for the de novo conversion of ribonucleoside diphosphates into deoxyribonucleoside diphosphates, which are essential for DNA synthesis and repair.
  • There are three types of this enzyme differing in their cofactors.
  • Class Ia enzymes contain a diiron(III)-tyrosyl radical, class Ib enzymes contain a dimanganese-tyrosyl radical, and class II enzymes contain adenosylcobalamin.
  • In all cases the cofactors are involved in generation of a transient thiyl (sulfanyl) radical on a cysteine residue, which attacks the substrate, forming a ribonucleotide 3'-radical, followed by water loss to form a ketyl (alpha-oxoalkyl) radical.
  • The ketyl radical is reduced to 3'-keto-deoxynucleotide concomitant with formation of a disulfide anion radical between two cysteine residues.
  • A proton-coupled electron-transfer from the disulfide radical to the substrate generates a 3'-deoxynucleotide radical, and the the final product is formed when the hydrogen atom that was initially removed from the 3'-position of the nucleotide by the thiyl radical is returned to the same position.
  • The disulfide bridge is reduced by the action of thioredoxin.
  • Cf. EC 1.1.98.6 and EC 1.17.4.2.
Cross-references
PROSITEPDOC00084 ; PDOC00317
BRENDA1.17.4.1
EC2PDB1.17.4.1
ExplorEnz1.17.4.1
PRIAM enzyme-specific profiles1.17.4.1
KEGG Ligand Database for Enzyme Nomenclature1.17.4.1
IUBMB Enzyme Nomenclature1.17.4.1
IntEnz1.17.4.1
MEDLINEFind literature relating to 1.17.4.1
MetaCyc1.17.4.1
UniProtKB/Swiss-Prot
O64174, BNRDF_BPSPB;  E7FHX6, NDRZ_PYRFU;  Q9HI70, NDRZ_THEAC;  
O31875, NRDEB_BACSU;  O64173, NRDEB_BPSPB;  Q8UEM4, NRDJ_AGRFC;  
Q6MNP6, NRDJ_BDEBA;  Q89MB9, NRDJ_BRADU;  Q72S00, NRDJ_LEPIC;  
Q8F3P1, NRDJ_LEPIN;  Q7UI46, NRDJ_RHOBA;  Q82KE2, NRDJ_STRAW;  
O54196, NRDJ_STRC2;  O69981, NRDJ_STRCO;  Q9XD73, NRDJ_STRCT;  
P9WH76, NRDZ_MYCTO;  P9WH77, NRDZ_MYCTU;  P0DKH3, RI2BL_ARATH;  
P0CG99, RIR1A_MYCS2;  P0CH00, RIR1B_MYCS2;  O36411, RIR1_ALHV1;  
O66503, RIR1_AQUAE;  Q9SJ20, RIR1_ARATH;  P42491, RIR1_ASFB7;  
P0C8H7, RIR1_ASFK5;  P26685, RIR1_ASFM2;  P0C8H8, RIR1_ASFP4;  
P0C8H9, RIR1_ASFWA;  P50620, RIR1_BACSU;  P50646, RIR1_BHV1C;  
P32282, RIR1_BPT4;  P57276, RIR1_BUCAI;  Q8K9W3, RIR1_BUCAP;  
Q89AS4, RIR1_BUCBP;  Q03604, RIR1_CAEEL;  Q9PL93, RIR1_CHLMU;  
Q9Z6S5, RIR1_CHLPN;  O84834, RIR1_CHLTR;  O61065, RIR1_CRYPV;  
P79732, RIR1_DANRE;  Q54Q71, RIR1_DICDI;  P48591, RIR1_DROME;  
P0C702, RIR1_EBVA8;  P03190, RIR1_EBVB9;  Q3KSU5, RIR1_EBVG;  
P00452, RIR1_ECOLI;  P28846, RIR1_EHV1B;  Q66663, RIR1_EHV2;  
P50642, RIR1_EHV4;  Q8SR37, RIR1_ENCCU;  Q6GZT8, RIR1_FRG3G;  
Q77MS1, RIR1_GAHVM;  P43754, RIR1_HAEIN;  Q9ZLF9, RIR1_HELPJ;  
P55982, RIR1_HELPY;  P08543, RIR1_HHV11;  P09853, RIR1_HHV23;  
P89462, RIR1_HHV2H;  Q2HR67, RIR1_HHV8P;  P23921, RIR1_HUMAN;  
Q196Z5, RIR1_IIV3;  O55716, RIR1_IIV6;  Q7T6Y8, RIR1_MIMIV;  
P07742, RIR1_MOUSE;  P0A5W9, RIR1_MYCBO;  P47473, RIR1_MYCGE;  
Q9CBQ0, RIR1_MYCLE;  P78027, RIR1_MYCPN;  P9WH74, RIR1_MYCTO;  
P9WH75, RIR1_MYCTU;  Q9UW15, RIR1_NEUCR;  Q6R7H4, RIR1_OSHVF;  
P50648, RIR1_PLAF4;  P50647, RIR1_PLAFG;  Q5R919, RIR1_PONAB;  
Q6UDJ2, RIR1_PSHV1;  P37426, RIR1_SALTY;  P36602, RIR1_SCHPO;  
Q01037, RIR1_SHV21;  P50643, RIR1_SUHVK;  P74240, RIR1_SYNY3;  
O83972, RIR1_TREPA;  O15909, RIR1_TRYBB;  Q76RD8, RIR1_VACCA;  
P20503, RIR1_VACCC;  P12848, RIR1_VACCW;  P32984, RIR1_VAR67;  
P09248, RIR1_VZVD;  Q4JQV6, RIR1_VZVO;  P21524, RIR1_YEAST;  
P50651, RIR2A_ARATH;  P9WH72, RIR2A_MYCTO;  P9WH73, RIR2A_MYCTU;  
Q7LG56, RIR2B_HUMAN;  Q4R741, RIR2B_MACFA;  Q6PEE3, RIR2B_MOUSE;  
P9WH70, RIR2B_MYCTO;  P9WH71, RIR2B_MYCTU;  Q5R9G0, RIR2B_PONAB;  
Q9LSD0, RIR2C_ARATH;  O36410, RIR2_ALHV1;  O67475, RIR2_AQUAE;  
P42492, RIR2_ASFB7;  P0C8I0, RIR2_ASFK5;  P26713, RIR2_ASFM2;  
P0C8I1, RIR2_ASFP4;  P0C8I2, RIR2_ASFWA;  Q9KFH7, RIR2_BACHD;  
P50621, RIR2_BACSU;  Q01319, RIR2_BHV1C;  P11156, RIR2_BPT4;  
P57275, RIR2_BUCAI;  Q8K9W4, RIR2_BUCAP;  Q89AS5, RIR2_BUCBP;  
P42170, RIR2_CAEEL;  Q9PL92, RIR2_CHLMU;  Q9Z6S4, RIR2_CHLPN;  
O84835, RIR2_CHLTR;  P79733, RIR2_DANRE;  P42521, RIR2_DICDI;  
P48592, RIR2_DROME;  P0CAP7, RIR2_EBVA8;  P0CAP6, RIR2_EBVB9;  
P0C701, RIR2_EBVG;  P69925, RIR2_ECO57;  P69924, RIR2_ECOLI;  
P28847, RIR2_EHV1B;  Q66662, RIR2_EHV2;  P50644, RIR2_EHV4;  
Q8SRR2, RIR2_ENCCU;  Q6GZQ8, RIR2_FRG3G;  Q77MS0, RIR2_GAHVM;  
P43755, RIR2_HAEIN;  Q9ZKC3, RIR2_HELPJ;  P55983, RIR2_HELPY;  
P10224, RIR2_HHV11;  P06474, RIR2_HHV1K;  P69520, RIR2_HHV23;  
P69521, RIR2_HHV2H;  F5HAW0, RIR2_HHV8P;  P31350, RIR2_HUMAN;  
Q197B2, RIR2_IIV3;  Q91FE8, RIR2_IIV6;  O46310, RIR2_LEIAM;  
Q4R7Q7, RIR2_MACFA;  Q60561, RIR2_MESAU;  Q7T6Y9, RIR2_MIMIV;  
P11157, RIR2_MOUSE;  Q9XC20, RIR2_MYCGA;  P47471, RIR2_MYCGE;  
Q9CBQ2, RIR2_MYCLE;  P75461, RIR2_MYCPN;  Q9C167, RIR2_NEUCR;  
Q6R7K3, RIR2_OSHVF;  P50650, RIR2_PLAF4;  P50649, RIR2_PLAFG;  
Q6UDJ1, RIR2_PSHV1;  Q4KLN6, RIR2_RAT;  Q9QTF2, RIR2_RSIV;  
P37427, RIR2_SALTY;  P36603, RIR2_SCHPO;  Q01038, RIR2_SHV21;  
P07201, RIR2_SPISO;  P50645, RIR2_SUHVK;  P32209, RIR2_SWPVK;  
P49730, RIR2_TOBAC;  O83092, RIR2_TREPA;  O15910, RIR2_TRYBB;  
O57175, RIR2_VACCA;  P20493, RIR2_VACCC;  P29883, RIR2_VACCP;  
P11158, RIR2_VACCW;  P33799, RIR2_VAR67;  P09247, RIR2_VZVD;  
Q4JQV7, RIR2_VZVO;  P09938, RIR2_YEAST;  Q9DHU2, RIR2_YLDV;  
P39452, RIR3_ECOLI;  Q08698, RIR3_SALTY;  P21672, RIR3_YEAST;  
P37146, RIR4_ECOLI;  P17424, RIR4_SALTY;  P49723, RIR4_YEAST;  
O30601, YOSP_BACSU;  

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All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.17.4.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.17.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.-.-.-