ID   RIR2A_ARATH             Reviewed;         341 AA.
AC   P50651; Q9LUH0;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   10-JAN-2003, sequence version 2.
DT   27-MAR-2024, entry version 171.
DE   RecName: Full=Ribonucleoside-diphosphate reductase small chain A;
DE            EC=1.17.4.1;
DE   AltName: Full=Ribonucleoside-diphosphate reductase R2A subunit;
DE            Short=AtRNR2;
DE            Short=Protein R2at;
DE   AltName: Full=Ribonucleotide reductase small subunit A;
GN   Name=RNR2A; Synonyms=RNR2; OrderedLocusNames=At3g23580;
GN   ORFNames=MDB19.6;
OS   Arabidopsis thaliana (Mouse-ear cress).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX   NCBI_TaxID=3702;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND DEVELOPMENTAL STAGE.
RC   STRAIN=cv. Columbia;
RX   PubMed=7821432; DOI=10.1016/0014-5793(94)01397-j;
RA   Philipps G., Clement B., Gigot C.;
RT   "Molecular characterization and cell cycle-regulated expression of a cDNA
RT   clone from Arabidopsis thaliana homologous to the small subunit of
RT   ribonucleotide reductase.";
RL   FEBS Lett. 358:67-70(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=10819329; DOI=10.1093/dnares/7.2.131;
RA   Sato S., Nakamura Y., Kaneko T., Katoh T., Asamizu E., Tabata S.;
RT   "Structural analysis of Arabidopsis thaliana chromosome 3. I. Sequence
RT   features of the regions of 4,504,864 bp covered by sixty P1 and TAC
RT   clones.";
RL   DNA Res. 7:131-135(2000).
RN   [3]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RX   PubMed=27862469; DOI=10.1111/tpj.13415;
RA   Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA   Town C.D.;
RT   "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT   genome.";
RL   Plant J. 89:789-804(2017).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=14593172; DOI=10.1126/science.1088305;
RA   Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M.,
RA   Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G.,
RA   Liu S.X., Lam B., Sakano H., Wu T., Yu G., Miranda M., Quach H.L.,
RA   Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C.,
RA   Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J.,
RA   Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A.,
RA   Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C.,
RA   Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X.,
RA   Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M.,
RA   Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K.,
RA   Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A.,
RA   Ecker J.R.;
RT   "Empirical analysis of transcriptional activity in the Arabidopsis
RT   genome.";
RL   Science 302:842-846(2003).
RN   [5]
RP   FUNCTION, COFACTOR, AND SUBUNIT.
RX   DOI=10.1007/s007750050173;
RA   Sauge-Merle S., Laulhere J.-P., Coves J., Le Pape L., Menage S.,
RA   Fontecave M.;
RT   "Ribonucleotide reductase from the higher plant Arabidopsis thaliana:
RT   expression of the R2 component and characterization of its iron-radical
RT   center.";
RL   J. Biol. Inorg. Chem. 2:586-594(1997).
RN   [6]
RP   ACTIVITY REGULATION.
RX   PubMed=9874215; DOI=10.1046/j.1432-1327.1998.2580485.x;
RA   Elleingand E., Gerez C., Un S., Knuepling M., Lu G., Salem J., Rubin H.,
RA   Sauge-Merle S., Laulhere J.-P., Fontecave M.;
RT   "Reactivity studies of the tyrosyl radical in ribonucleotide reductase from
RT   Mycobacterium tuberculosis and Arabidopsis thaliana -- comparison with
RT   Escherichia coli and mouse.";
RL   Eur. J. Biochem. 258:485-490(1998).
RN   [7]
RP   TISSUE SPECIFICITY, FUNCTION, AND DISRUPTION PHENOTYPE.
RX   PubMed=16399800; DOI=10.1105/tpc.105.037044;
RA   Wang C., Liu Z.;
RT   "Arabidopsis ribonucleotide reductases are critical for cell cycle
RT   progression, DNA damage repair, and plant development.";
RL   Plant Cell 18:350-365(2006).
RN   [8]
RP   INTERACTION WITH CSN7, SUBUNIT, AND TISSUE SPECIFICITY.
RX   PubMed=21614643; DOI=10.1007/s11103-011-9795-8;
RA   Halimi Y., Dessau M., Pollak S., Ast T., Erez T., Livnat-Levanon N.,
RA   Karniol B., Hirsch J.A., Chamovitz D.A.;
RT   "COP9 signalosome subunit 7 from Arabidopsis interacts with and regulates
RT   the small subunit of ribonucleotide reductase (RNR2).";
RL   Plant Mol. Biol. 77:77-89(2011).
CC   -!- FUNCTION: Provides the precursors necessary for DNA synthesis.
CC       Catalyzes the biosynthesis of deoxyribonucleotides from the
CC       corresponding ribonucleotides. {ECO:0000269|PubMed:16399800,
CC       ECO:0000269|Ref.5}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-disulfide + a 2'-deoxyribonucleoside 5'-
CC         diphosphate + H2O = [thioredoxin]-dithiol + a ribonucleoside 5'-
CC         diphosphate; Xref=Rhea:RHEA:23252, Rhea:RHEA-COMP:10698, Rhea:RHEA-
CC         COMP:10700, ChEBI:CHEBI:15377, ChEBI:CHEBI:29950, ChEBI:CHEBI:50058,
CC         ChEBI:CHEBI:57930, ChEBI:CHEBI:73316; EC=1.17.4.1;
CC         Evidence={ECO:0000255|PROSITE-ProRule:PRU10014};
CC   -!- COFACTOR:
CC       Name=Fe cation; Xref=ChEBI:CHEBI:24875; Evidence={ECO:0000269|Ref.5};
CC       Note=Binds 2 iron ions per subunit. {ECO:0000269|Ref.5};
CC   -!- ACTIVITY REGULATION: Inhibited by phenol, paracetamol, 2,4,6-
CC       trimethylphenol, resveratrol, furfuryl mercaptan, 2-thiophenthiol,
CC       phenylhydrazine, and hydroxyurea. {ECO:0000269|PubMed:9874215}.
CC   -!- SUBUNIT: Homodimer and heterodimer with TSO2. Heterotetramer of two R1
CC       and two R2 chains. A radical transfer pathway may occur between Tyr-125
CC       of protein R2 and R1. Homodimer contains a dinuclear non-heme iron
CC       center and a stable tyrosyl radical essential for activity. A transfer
CC       pathway may occur between Tyr-125 of protein R2 and R1. Interacts with
CC       CSN7. {ECO:0000269|PubMed:21614643, ECO:0000269|Ref.5}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed in rosette leaves, cauline leaves, stems
CC       and flowers. {ECO:0000269|PubMed:16399800,
CC       ECO:0000269|PubMed:21614643}.
CC   -!- DEVELOPMENTAL STAGE: Accumulated during S phase of the cell cycle.
CC       {ECO:0000269|PubMed:7821432}.
CC   -!- DISRUPTION PHENOTYPE: No visible phenotype, due to the redundancy with
CC       RNR2B and TSO2. Rnr2a and rnr2b double mutants have no visible
CC       phenotype. {ECO:0000269|PubMed:16399800}.
CC   -!- MISCELLANEOUS: A substrate-binding catalytic site, located on R1, is
CC       formed only in the presence of the second subunit R2.
CC   -!- SIMILARITY: Belongs to the ribonucleoside diphosphate reductase small
CC       chain family. {ECO:0000305}.
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DR   EMBL; X77336; CAA54549.1; -; mRNA.
DR   EMBL; AB023036; BAB02776.1; -; Genomic_DNA.
DR   EMBL; CP002686; AEE76779.1; -; Genomic_DNA.
DR   EMBL; AF372971; AAK50108.1; -; mRNA.
DR   EMBL; AY143893; AAN28832.1; -; mRNA.
DR   PIR; S68538; S68538.
DR   RefSeq; NP_189000.1; NM_113261.4.
DR   AlphaFoldDB; P50651; -.
DR   SMR; P50651; -.
DR   BioGRID; 7269; 1.
DR   STRING; 3702.P50651; -.
DR   PaxDb; 3702-AT3G23580-1; -.
DR   ProteomicsDB; 236265; -.
DR   EnsemblPlants; AT3G23580.1; AT3G23580.1; AT3G23580.
DR   GeneID; 821937; -.
DR   Gramene; AT3G23580.1; AT3G23580.1; AT3G23580.
DR   KEGG; ath:AT3G23580; -.
DR   Araport; AT3G23580; -.
DR   TAIR; AT3G23580; RNR2A.
DR   eggNOG; KOG1567; Eukaryota.
DR   HOGENOM; CLU_035339_2_1_1; -.
DR   InParanoid; P50651; -.
DR   OMA; FMVAVHA; -.
DR   OrthoDB; 5487627at2759; -.
DR   PhylomeDB; P50651; -.
DR   BioCyc; ARA:AT3G23580-MONOMER; -.
DR   BioCyc; MetaCyc:AT3G23580-MONOMER; -.
DR   BRENDA; 1.17.4.1; 399.
DR   BRENDA; 1.17.4.2; 399.
DR   PRO; PR:P50651; -.
DR   Proteomes; UP000006548; Chromosome 3.
DR   ExpressionAtlas; P50651; baseline and differential.
DR   GO; GO:0005971; C:ribonucleoside-diphosphate reductase complex; ISS:TAIR.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0004748; F:ribonucleoside-diphosphate reductase activity, thioredoxin disulfide as acceptor; IDA:TAIR.
DR   GO; GO:0009263; P:deoxyribonucleotide biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0006281; P:DNA repair; TAS:TAIR.
DR   GO; GO:0051726; P:regulation of cell cycle; IMP:TAIR.
DR   GO; GO:0009259; P:ribonucleotide metabolic process; TAS:TAIR.
DR   CDD; cd01049; RNRR2; 1.
DR   Gene3D; 1.10.620.20; Ribonucleotide Reductase, subunit A; 1.
DR   InterPro; IPR009078; Ferritin-like_SF.
DR   InterPro; IPR012348; RNR-like.
DR   InterPro; IPR033909; RNR_small.
DR   InterPro; IPR030475; RNR_small_AS.
DR   InterPro; IPR000358; RNR_small_fam.
DR   PANTHER; PTHR23409; RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE SMALL CHAIN; 1.
DR   PANTHER; PTHR23409:SF35; RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE SMALL CHAIN A; 1.
DR   Pfam; PF00268; Ribonuc_red_sm; 1.
DR   PIRSF; PIRSF000355; NrdB; 1.
DR   SUPFAM; SSF47240; Ferritin-like; 1.
DR   PROSITE; PS00368; RIBORED_SMALL; 1.
DR   Genevisible; P50651; AT.
PE   1: Evidence at protein level;
KW   Cytoplasm; Deoxyribonucleotide synthesis; Iron; Metal-binding;
KW   Oxidoreductase; Reference proteome.
FT   CHAIN           1..341
FT                   /note="Ribonucleoside-diphosphate reductase small chain A"
FT                   /id="PRO_0000190466"
FT   REGION          1..20
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        125
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10014"
FT   BINDING         87
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10014"
FT   BINDING         118
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10014"
FT   BINDING         118
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   BINDING         121
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10014"
FT   BINDING         180
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   BINDING         214
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   BINDING         217
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   CONFLICT        95
FT                   /note="Missing (in Ref. 1; CAA54549)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        179
FT                   /note="V -> A (in Ref. 1; CAA54549)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        225
FT                   /note="Y -> I (in Ref. 1; CAA54549)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        230..232
FT                   /note="KQL -> LHV (in Ref. 1; CAA54549)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   341 AA;  39370 MW;  3214A88AE7B7776A CRC64;
     MGSLKEGQGR DMEEGESEEP LLMAQNQRFT MFPIRYKSIW EMYKKAEASF WTAEEVDLST
     DVQQWEALTD SEKHFISHIL AFFAASDGIV LENLAARFLN DVQVPEARAF YGFQIAMENI
     HSEMYSLLLE TFIKDSKEKD RLFNAIETIP CISKKAKWCL DWIQSPMSFA VRLVAFACVE
     GIFFSGSFCA IFWLKKRGLM PGLTFSNELI SRDEGLHCDF ACLLYSLLQK QLPLEKVYQI
     VHEAVEIETE FVCKALPCDL IGMNSNLMSQ YIQFVADRLL VTLGCERTYK AENPFDWMEF
     ISLQGKTNFF EKRVGEYQKA SVMSNLQNGN QNYEFTTEED F
//