ID   APR3_ARATH              Reviewed;         458 AA.
AC   P92980; C0Z2S3; O48887; Q38948; Q8LAV2;
DT   19-OCT-2002, integrated into UniProtKB/Swiss-Prot.
DT   19-OCT-2002, sequence version 2.
DT   02-SEP-2026, entry version 189.
DE   RecName: Full=5'-adenylylsulfate reductase 3, chloroplastic;
DE            EC=1.8.4.9;
DE   AltName: Full=3'-phosphoadenosine-5'-phosphosulfate reductase homolog 26;
DE            Short=PAPS reductase homolog 26;
DE            Short=Prh-26;
DE   AltName: Full=Adenosine 5'-phosphosulfate 5'-adenylylsulfate sulfotransferase 3;
DE            Short=APS sulfotransferase 3;
DE   AltName: Full=Thioredoxin-independent APS reductase 3;
DE   Flags: Precursor;
GN   Name=APR3; Synonyms=PRH26; OrderedLocusNames=At4g21990;
GN   ORFNames=F1N20.90;
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].
RC   STRAIN=cv. Columbia;
RX   PubMed=8917599; DOI=10.1073/pnas.93.23.13377;
RA   Gutierrez-Marcos J.F., Roberts M.A., Campbell E.I., Wray J.L.;
RT   "Three members of a novel small gene-family from Arabidopsis thaliana able
RT   to complement functionally an Escherichia coli mutant defective in PAPS
RT   reductase activity encode proteins with a thioredoxin-like domain and 'APS
RT   reductase' activity.";
RL   Proc. Natl. Acad. Sci. U.S.A. 93:13377-13382(1996).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=8917600; DOI=10.1073/pnas.93.23.13383;
RA   Setya A., Murillo M., Leustek T.;
RT   "Sulfate reduction in higher plants: molecular evidence for a novel 5'-
RT   adenylylsulfate reductase.";
RL   Proc. Natl. Acad. Sci. U.S.A. 93:13383-13388(1996).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RA   Chen Y.C., Leustek T.;
RT   "Three genomic clones from Arabidopsis thaliana encoding 5'-adenylysulfate
RT   reductase.";
RL   (er) Plant Gene Register PGR98-030(1998).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=10617198; DOI=10.1038/47134;
RA   Mayer K.F.X., Schueller C., Wambutt R., Murphy G., Volckaert G., Pohl T.,
RA   Duesterhoeft A., Stiekema W., Entian K.-D., Terryn N., Harris B.,
RA   Ansorge W., Brandt P., Grivell L.A., Rieger M., Weichselgartner M.,
RA   de Simone V., Obermaier B., Mache R., Mueller M., Kreis M., Delseny M.,
RA   Puigdomenech P., Watson M., Schmidtheini T., Reichert B., Portetelle D.,
RA   Perez-Alonso M., Boutry M., Bancroft I., Vos P., Hoheisel J.,
RA   Zimmermann W., Wedler H., Ridley P., Langham S.-A., McCullagh B.,
RA   Bilham L., Robben J., van der Schueren J., Grymonprez B., Chuang Y.-J.,
RA   Vandenbussche F., Braeken M., Weltjens I., Voet M., Bastiaens I., Aert R.,
RA   Defoor E., Weitzenegger T., Bothe G., Ramsperger U., Hilbert H., Braun M.,
RA   Holzer E., Brandt A., Peters S., van Staveren M., Dirkse W., Mooijman P.,
RA   Klein Lankhorst R., Rose M., Hauf J., Koetter P., Berneiser S., Hempel S.,
RA   Feldpausch M., Lamberth S., Van den Daele H., De Keyser A., Buysshaert C.,
RA   Gielen J., Villarroel R., De Clercq R., van Montagu M., Rogers J.,
RA   Cronin A., Quail M.A., Bray-Allen S., Clark L., Doggett J., Hall S.,
RA   Kay M., Lennard N., McLay K., Mayes R., Pettett A., Rajandream M.A.,
RA   Lyne M., Benes V., Rechmann S., Borkova D., Bloecker H., Scharfe M.,
RA   Grimm M., Loehnert T.-H., Dose S., de Haan M., Maarse A.C., Schaefer M.,
RA   Mueller-Auer S., Gabel C., Fuchs M., Fartmann B., Granderath K., Dauner D.,
RA   Herzl A., Neumann S., Argiriou A., Vitale D., Liguori R., Piravandi E.,
RA   Massenet O., Quigley F., Clabauld G., Muendlein A., Felber R., Schnabl S.,
RA   Hiller R., Schmidt W., Lecharny A., Aubourg S., Chefdor F., Cooke R.,
RA   Berger C., Monfort A., Casacuberta E., Gibbons T., Weber N., Vandenbol M.,
RA   Bargues M., Terol J., Torres A., Perez-Perez A., Purnelle B., Bent E.,
RA   Johnson S., Tacon D., Jesse T., Heijnen L., Schwarz S., Scholler P.,
RA   Heber S., Francs P., Bielke C., Frishman D., Haase D., Lemcke K.,
RA   Mewes H.-W., Stocker S., Zaccaria P., Bevan M., Wilson R.K.,
RA   de la Bastide M., Habermann K., Parnell L., Dedhia N., Gnoj L., Schutz K.,
RA   Huang E., Spiegel L., Sekhon M., Murray J., Sheet P., Cordes M.,
RA   Abu-Threideh J., Stoneking T., Kalicki J., Graves T., Harmon G.,
RA   Edwards J., Latreille P., Courtney L., Cloud J., Abbott A., Scott K.,
RA   Johnson D., Minx P., Bentley D., Fulton B., Miller N., Greco T., Kemp K.,
RA   Kramer J., Fulton L., Mardis E., Dante M., Pepin K., Hillier L.W.,
RA   Nelson J., Spieth J., Ryan E., Andrews S., Geisel C., Layman D., Du H.,
RA   Ali J., Berghoff A., Jones K., Drone K., Cotton M., Joshu C., Antonoiu B.,
RA   Zidanic M., Strong C., Sun H., Lamar B., Yordan C., Ma P., Zhong J.,
RA   Preston R., Vil D., Shekher M., Matero A., Shah R., Swaby I.K.,
RA   O'Shaughnessy A., Rodriguez M., Hoffman J., Till S., Granat S., Shohdy N.,
RA   Hasegawa A., Hameed A., Lodhi M., Johnson A., Chen E., Marra M.A.,
RA   Martienssen R., McCombie W.R.;
RT   "Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana.";
RL   Nature 402:769-777(1999).
RN   [5]
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   [6]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RG   The Arabidopsis Information Resource (TAIR);
RT   "Community-consensus reference genome of Arabidopsis thaliana Col-0.";
RL   Submitted (FEB-2026) to the EMBL/GenBank/DDBJ databases.
RN   [7]
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   [8]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia; TISSUE=Rosette leaf;
RX   PubMed=19423640; DOI=10.1093/dnares/dsp009;
RA   Iida K., Fukami-Kobayashi K., Toyoda A., Sakaki Y., Kobayashi M., Seki M.,
RA   Shinozaki K.;
RT   "Analysis of multiple occurrences of alternative splicing events in
RT   Arabidopsis thaliana using novel sequenced full-length cDNAs.";
RL   DNA Res. 16:155-164(2009).
RN   [9]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RA   Brover V.V., Troukhan M.E., Alexandrov N.A., Lu Y.-P., Flavell R.B.,
RA   Feldmann K.A.;
RT   "Full-length cDNA from Arabidopsis thaliana.";
RL   Submitted (MAR-2002) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Reduces sulfate for Cys biosynthesis. Substrate preference is
CC       adenosine-5'-phosphosulfate (APS) >> 3'-phosphoadenosine-5'-
CC       phosphosulfate (PAPS). Uses glutathione or DTT as source of protons.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=glutathione disulfide + sulfite + AMP + 2 H(+) = adenosine 5'-
CC         phosphosulfate + 2 glutathione; Xref=Rhea:RHEA:14141,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:17359, ChEBI:CHEBI:57925,
CC         ChEBI:CHEBI:58243, ChEBI:CHEBI:58297, ChEBI:CHEBI:456215; EC=1.8.4.9;
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000250};
CC       Note=Binds 1 [4Fe-4S] cluster. {ECO:0000250};
CC   -!- ACTIVITY REGULATION: Stimulated by sodium sulfate > ammonium sulfate.
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast {ECO:0000305}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=1;
CC         Comment=A number of isoforms are produced. According to EST
CC         sequences.;
CC       Name=1;
CC         IsoId=P92980-1; Sequence=Displayed;
CC   -!- TISSUE SPECIFICITY: Leaves, roots and stem.
CC   -!- INDUCTION: By sulfate starvation.
CC   -!- DOMAIN: The C-terminal domain may function as glutaredoxin and mediates
CC       the interaction of the enzyme with glutathione (GSH). Active in GSH-
CC       dependent reduction of hydroxyethyldisulfide, cystine,
CC       dehydroascorbate, insulin disulfides and ribonucleotide reductase (By
CC       similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the APS reductase family. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAC26978.1; Type=Frameshift; Evidence={ECO:0000305};
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DR   EMBL; U53865; AAC49562.1; -; mRNA.
DR   EMBL; U56922; AAC26978.1; ALT_FRAME; mRNA.
DR   EMBL; AF016284; AAC26981.1; -; Genomic_DNA.
DR   EMBL; AL022140; CAA18102.1; -; Genomic_DNA.
DR   EMBL; AL161556; CAB79154.1; -; Genomic_DNA.
DR   EMBL; CP002687; AEE84539.1; -; Genomic_DNA.
DR   EMBL; OZ408686; CAO7048214.1; -; Genomic_DNA.
DR   EMBL; AF428445; AAL16214.1; -; mRNA.
DR   EMBL; AY054175; AAL06836.1; -; mRNA.
DR   EMBL; AY062665; AAL32743.1; -; mRNA.
DR   EMBL; AY093319; AAM13318.1; -; mRNA.
DR   EMBL; AY103313; AAM65364.1; -; mRNA.
DR   EMBL; AK318887; BAH57002.1; -; mRNA.
DR   EMBL; AY087591; AAM65133.1; -; mRNA.
DR   PIR; T49106; T49106.
DR   RefSeq; NP_193930.1; NM_118320.3. [P92980-1]
DR   AlphaFoldDB; P92980; -.
DR   SMR; P92980; -.
DR   BioGRID; 13577; 1.
DR   FunCoup; P92980; 239.
DR   IntAct; P92980; 2.
DR   STRING; 3702.P92980; -.
DR   iPTMnet; P92980; -.
DR   PaxDb; 3702-P92980; -.
DR   ProteomicsDB; 244440; -. [P92980-1]
DR   GeneID; 828288; -.
DR   KEGG; ath:AT4G21990; -.
DR   Araport; AT4G21990; -.
DR   TAIR; AT4G21990; APR3.
DR   eggNOG; KOG0189; Eukaryota.
DR   eggNOG; KOG0191; Eukaryota.
DR   InParanoid; P92980; -.
DR   PhylomeDB; P92980; -.
DR   BioCyc; MetaCyc:AT4G21990-MONOMER; -.
DR   PRO; PR:P92980; -.
DR   Proteomes; UP000006548; Chromosome 4.
DR   ExpressionAtlas; P92980; baseline and differential.
DR   GO; GO:0009507; C:chloroplast; HDA:TAIR.
DR   GO; GO:0005737; C:cytoplasm; ISM:TAIR.
DR   GO; GO:0033741; F:adenylyl-sulfate reductase (glutathione) activity; IEA:UniProtKB-EC.
DR   GO; GO:0009973; F:adenylyl-sulfate reductase activity; IDA:TAIR.
DR   GO; GO:0004604; F:phosphoadenylyl-sulfate reductase (thioredoxin) activity; IEA:InterPro.
DR   GO; GO:0000103; P:sulfate assimilation; IDA:TAIR.
DR   GO; GO:0019379; P:sulfate assimilation, phosphoadenylyl sulfate reduction by phosphoadenylyl-sulfate reductase (thioredoxin); IEA:InterPro.
DR   CDD; cd23945; PAPS_reductase; 1.
DR   CDD; cd02993; PDI_a_APS_reductase; 1.
DR   FunFam; 3.40.50.620:FF:000153; Phosphoadenosine phosphosulfate reductase; 1.
DR   FunFam; 3.40.30.10:FF:000252; Phosphoadenosine-phosphosulphate reductase; 1.
DR   Gene3D; 3.40.30.10; Glutaredoxin; 1.
DR   Gene3D; 3.40.50.620; HUPs; 1.
DR   HAMAP; MF_00063; CysH; 1.
DR   InterPro; IPR004511; PAPS/APS_Rdtase.
DR   InterPro; IPR002500; PAPS_reduct_dom.
DR   InterPro; IPR014729; Rossmann-like_a/b/a_fold.
DR   InterPro; IPR004508; Thioredoxin-indep_APS_Rdtase.
DR   InterPro; IPR036249; Thioredoxin-like_sf.
DR   InterPro; IPR013766; Thioredoxin_domain.
DR   NCBIfam; TIGR00424; APS_reduc; 1.
DR   NCBIfam; NF002537; PRK02090.1; 1.
DR   PANTHER; PTHR46482; 5'-ADENYLYLSULFATE REDUCTASE 3, CHLOROPLASTIC; 1.
DR   PANTHER; PTHR46482:SF14; 5'-ADENYLYLSULFATE REDUCTASE 3, CHLOROPLASTIC; 1.
DR   Pfam; PF01507; PAPS_reduct; 1.
DR   Pfam; PF00085; Thioredoxin; 1.
DR   SUPFAM; SSF52402; Adenine nucleotide alpha hydrolases-like; 1.
DR   SUPFAM; SSF52833; Thioredoxin-like; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
PE   2: Evidence at transcript level;
KW   4Fe-4S; Alternative splicing; Amino-acid biosynthesis; Chloroplast;
KW   Cysteine biosynthesis; Disulfide bond; Iron; Iron-sulfur; Metal-binding;
KW   Oxidoreductase; Plastid; Redox-active center; Reference proteome;
KW   Stress response; Transit peptide.
FT   TRANSIT         1..69
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           70..458
FT                   /note="5'-adenylylsulfate reductase 3, chloroplastic"
FT                   /id="PRO_0000023216"
FT   DOMAIN          337..458
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   REGION          1..24
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          70..319
FT                   /note="Reductase domain"
FT   COMPBIAS        8..23
FT                   /note="Low complexity"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        378
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        381
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   DISULFID        378..381
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   CONFLICT        28
FT                   /note="T -> A (in Ref. 2; AAC26978)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        121
FT                   /note="D -> Y (in Ref. 2; AAC26978)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        264
FT                   /note="N -> D (in Ref. 8; BAH57002)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        338
FT                   /note="S -> T (in Ref. 9; AAM65133)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        375
FT                   /note="A -> R (in Ref. 1; AAC49562)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        436
FT                   /note="R -> I (in Ref. 1; AAC49562)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   458 AA;  50695 MW;  E950C28E15F418CB CRC64;
     MALAINVSSS SSSAISSSSF PSSDLKVTKI GSLRLLNRTN VSAASLSLSG KRSSVKALNV
     QSITKESIVA SEVTEKLDVV EVEDFEELAK RLENASPLEI MDKALEKFGN DIAIAFSGAE
     DVALIEYAHL TGRPYRVFSL DTGRLNPETY RLFDTVEKHY GIRIEYMFPD AVEVQALVRN
     KGLFSFYEDG HQECCRIRKV RPLRRALKGL RAWITGQRKD QSPGTRSEIP VVQVDPVFEG
     LDGGVGSLVK WNPVANVEGN DVWNFLRTMD VPVNTLHAAG YVSIGCEPCT RAVLPGQHER
     EGRWWWEDAK AKECGLHKGN IKENTNGNAT ANVNGTASVA DIFNSENVVN LSRQGIENLM
     KLENRKEAWI VVLYAPWCPF CQAMEASFDE LADKLGGSGV KVAKFRADGD QKDFAKKELQ
     LGSFPTILVF PKNSSRPIKY PSEKRDVDSL TSFLNLVR
//