ID   APX2_ARATH              Reviewed;         251 AA.
AC   Q1PER6; Q39006; Q67XB1; Q9SF39;
DT   28-NOV-2006, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 3.
DT   02-SEP-2026, entry version 121.
DE   RecName: Full=L-ascorbate peroxidase 2, cytosolic {ECO:0000303|PubMed:9144965};
DE            EC=1.11.1.11 {ECO:0000305|PubMed:12609042};
DE   AltName: Full=L-ascorbate peroxidase 1b;
DE            Short=APX1b {ECO:0000303|PubMed:8580771};
DE            Short=AtAPx02 {ECO:0000303|PubMed:9144965};
GN   Name=APX2 {ECO:0000303|PubMed:9144965};
GN   Synonyms=APX1B {ECO:0000303|PubMed:8580771};
GN   OrderedLocusNames=At3g09640 {ECO:0000312|Araport:AT3G09640};
GN   ORFNames=F11F8_23 {ECO:0000312|EMBL:AAF23294.1};
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 [GENOMIC DNA].
RX   PubMed=8580771; DOI=10.1007/bf00197587;
RA   Santos M., Gosseau H., Lister C., Foyer C., Creissen G.P., Mullineaux P.M.;
RT   "Cytosolic ascorbate peroxidase from Arabidopsis thaliana L. is encoded by
RT   a small multigene family.";
RL   Planta 198:64-69(1996).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA], SUBCELLULAR LOCATION, AND INDUCTION.
RC   STRAIN=cv. Columbia; TISSUE=Leaf;
RX   PubMed=9144965; DOI=10.1105/tpc.9.4.627;
RA   Karpinski S., Escobar C., Karpinski B., Creissen G.P., Mullineaux P.M.;
RT   "Photosynthetic electron transport regulates the expression of cytosolic
RT   ascorbate peroxidase genes in Arabidopsis during excess light stress.";
RL   Plant Cell 9:627-640(1997).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=11130713; DOI=10.1038/35048706;
RA   Salanoubat M., Lemcke K., Rieger M., Ansorge W., Unseld M., Fartmann B.,
RA   Valle G., Bloecker H., Perez-Alonso M., Obermaier B., Delseny M.,
RA   Boutry M., Grivell L.A., Mache R., Puigdomenech P., De Simone V.,
RA   Choisne N., Artiguenave F., Robert C., Brottier P., Wincker P.,
RA   Cattolico L., Weissenbach J., Saurin W., Quetier F., Schaefer M.,
RA   Mueller-Auer S., Gabel C., Fuchs M., Benes V., Wurmbach E., Drzonek H.,
RA   Erfle H., Jordan N., Bangert S., Wiedelmann R., Kranz H., Voss H.,
RA   Holland R., Brandt P., Nyakatura G., Vezzi A., D'Angelo M., Pallavicini A.,
RA   Toppo S., Simionati B., Conrad A., Hornischer K., Kauer G., Loehnert T.-H.,
RA   Nordsiek G., Reichelt J., Scharfe M., Schoen O., Bargues M., Terol J.,
RA   Climent J., Navarro P., Collado C., Perez-Perez A., Ottenwaelder B.,
RA   Duchemin D., Cooke R., Laudie M., Berger-Llauro C., Purnelle B., Masuy D.,
RA   de Haan M., Maarse A.C., Alcaraz J.-P., Cottet A., Casacuberta E.,
RA   Monfort A., Argiriou A., Flores M., Liguori R., Vitale D., Mannhaupt G.,
RA   Haase D., Schoof H., Rudd S., Zaccaria P., Mewes H.-W., Mayer K.F.X.,
RA   Kaul S., Town C.D., Koo H.L., Tallon L.J., Jenkins J., Rooney T., Rizzo M.,
RA   Walts A., Utterback T., Fujii C.Y., Shea T.P., Creasy T.H., Haas B.,
RA   Maiti R., Wu D., Peterson J., Van Aken S., Pai G., Militscher J.,
RA   Sellers P., Gill J.E., Feldblyum T.V., Preuss D., Lin X., Nierman W.C.,
RA   Salzberg S.L., White O., Venter J.C., Fraser C.M., Kaneko T., Nakamura Y.,
RA   Sato S., Kato T., Asamizu E., Sasamoto S., Kimura T., Idesawa K.,
RA   Kawashima K., Kishida Y., Kiyokawa C., Kohara M., Matsumoto M., Matsuno A.,
RA   Muraki A., Nakayama S., Nakazaki N., Shinpo S., Takeuchi C., Wada T.,
RA   Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.";
RL   Nature 408:820-822(2000).
RN   [4]
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   [5]
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   [6]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RA   Totoki Y., Seki M., Ishida J., Nakajima M., Enju A., Kamiya A.,
RA   Narusaka M., Shin-i T., Nakagawa M., Sakamoto N., Oishi K., Kohara Y.,
RA   Kobayashi M., Toyoda A., Sakaki Y., Sakurai T., Iida K., Akiyama K.,
RA   Satou M., Toyoda T., Konagaya A., Carninci P., Kawai J., Hayashizaki Y.,
RA   Shinozaki K.;
RT   "Large-scale analysis of RIKEN Arabidopsis full-length (RAFL) cDNAs.";
RL   Submitted (SEP-2004) to the EMBL/GenBank/DDBJ databases.
RN   [7]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=17147637; DOI=10.1111/j.1467-7652.2006.00183.x;
RA   Underwood B.A., Vanderhaeghen R., Whitford R., Town C.D., Hilson P.;
RT   "Simultaneous high-throughput recombinational cloning of open reading
RT   frames in closed and open configurations.";
RL   Plant Biotechnol. J. 4:317-324(2006).
RN   [8]
RP   INDUCTION.
RX   PubMed=12068123; DOI=10.1104/pp.001362;
RA   Panchuk I.I., Volkov R.A., Schoffl F.;
RT   "Heat stress- and heat shock transcription factor-dependent expression and
RT   activity of ascorbate peroxidase in Arabidopsis.";
RL   Plant Physiol. 129:838-853(2002).
RN   [9]
RP   INDUCTION.
RX   PubMed=15086807; DOI=10.1111/j.1365-313x.2004.02066.x;
RA   Chang C.C., Ball L., Fryer M.J., Baker N.R., Karpinski S., Mullineaux P.M.;
RT   "Induction of ASCORBATE PEROXIDASE 2 expression in wounded Arabidopsis
RT   leaves does not involve known wound-signalling pathways but is associated
RT   with changes in photosynthesis.";
RL   Plant J. 38:499-511(2004).
RN   [10]
RP   FUNCTION, CATALYTIC ACTIVITY, INDUCTION, AND TISSUE SPECIFICITY.
RX   PubMed=12609042; DOI=10.1046/j.1365-313x.2003.01656.x;
RA   Fryer M.J., Ball L., Oxborough K., Karpinski S., Mullineaux P.M.,
RA   Baker N.R.;
RT   "Control of Ascorbate Peroxidase 2 expression by hydrogen peroxide and leaf
RT   water status during excess light stress reveals a functional organisation
RT   of Arabidopsis leaves.";
RL   Plant J. 33:691-705(2003).
CC   -!- FUNCTION: Plays a key role in hydrogen peroxide removal.
CC       {ECO:0000305|PubMed:12609042}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=L-ascorbate + H2O2 = L-dehydroascorbate + 2 H2O;
CC         Xref=Rhea:RHEA:22996, ChEBI:CHEBI:15377, ChEBI:CHEBI:16240,
CC         ChEBI:CHEBI:38290, ChEBI:CHEBI:58539; EC=1.11.1.11;
CC         Evidence={ECO:0000305|PubMed:12609042};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:22997;
CC         Evidence={ECO:0000305|PubMed:12609042};
CC   -!- COFACTOR:
CC       Name=heme b; Xref=ChEBI:CHEBI:60344;
CC       Note=Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit.;
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:9144965}.
CC   -!- TISSUE SPECIFICITY: Detected in bundle sheath cells, the photosynthetic
CC       cells that surround the phloem and xylem.
CC       {ECO:0000269|PubMed:12609042}.
CC   -!- INDUCTION: By excess light treatment, by wounding and by heat-shock
CC       stress. {ECO:0000269|PubMed:12068123, ECO:0000269|PubMed:12609042,
CC       ECO:0000269|PubMed:15086807, ECO:0000269|PubMed:9144965}.
CC   -!- MISCELLANEOUS: Binds one cation per subunit; probably K(+), but might
CC       also be Ca(2+). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the peroxidase family. Ascorbate peroxidase
CC       subfamily. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAF23294.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR   EMBL; X80036; CAA56340.1; -; Genomic_DNA.
DR   EMBL; X98275; CAA66925.1; -; mRNA.
DR   EMBL; AC016661; AAF23294.1; ALT_SEQ; Genomic_DNA.
DR   EMBL; CP002686; AEE74791.1; -; Genomic_DNA.
DR   EMBL; CP002686; AEE74792.1; -; Genomic_DNA.
DR   EMBL; OZ408685; CAO7040250.1; -; Genomic_DNA.
DR   EMBL; AK176821; BAD44584.1; -; mRNA.
DR   EMBL; AK176908; BAD44671.1; -; mRNA.
DR   EMBL; DQ446651; ABE65932.1; -; mRNA.
DR   RefSeq; NP_001030664.1; NM_001035587.3.
DR   RefSeq; NP_187575.2; NM_111798.4.
DR   AlphaFoldDB; Q1PER6; -.
DR   SMR; Q1PER6; -.
DR   FunCoup; Q1PER6; 276.
DR   STRING; 3702.Q1PER6; -.
DR   PeroxiBase; 1888; AtAPx02.
DR   PaxDb; 3702-Q1PER6; -.
DR   ProteomicsDB; 246597; -.
DR   GeneID; 820121; -.
DR   KEGG; ath:AT3G09640; -.
DR   Araport; AT3G09640; -.
DR   TAIR; AT3G09640; APX2.
DR   eggNOG; ENOG502QR1E; Eukaryota.
DR   HOGENOM; CLU_036959_3_0_1; -.
DR   InParanoid; Q1PER6; -.
DR   OMA; MGKCYPK; -.
DR   OrthoDB; 2859658at2759; -.
DR   PhylomeDB; Q1PER6; -.
DR   BioCyc; ARA:AT3G09640-MONOMER; -.
DR   BRENDA; 1.11.1.11; 399.
DR   PRO; PR:Q1PER6; -.
DR   Proteomes; UP000006548; Chromosome 3.
DR   ExpressionAtlas; Q1PER6; baseline and differential.
DR   GO; GO:0005737; C:cytoplasm; EXP:UniProtKB.
DR   GO; GO:0005829; C:cytosol; IDA:TAIR.
DR   GO; GO:0020037; F:heme binding; IEA:InterPro.
DR   GO; GO:0016688; F:L-ascorbate peroxidase activity; TAS:TAIR.
DR   GO; GO:0034599; P:cellular response to oxidative stress; IBA:GO_Central.
DR   GO; GO:0006979; P:response to oxidative stress; IDA:TAIR.
DR   CDD; cd00691; ascorbate_peroxidase; 1.
DR   FunFam; 1.10.520.10:FF:000003; Cytosolic ascorbate peroxidase; 1.
DR   FunFam; 1.10.420.10:FF:000003; L-ascorbate peroxidase, cytosolic; 1.
DR   Gene3D; 1.10.520.10; -; 1.
DR   Gene3D; 1.10.420.10; Peroxidase, domain 2; 1.
DR   InterPro; IPR044831; Ccp1-like.
DR   InterPro; IPR002016; Haem_peroxidase.
DR   InterPro; IPR010255; Haem_peroxidase_sf.
DR   InterPro; IPR002207; Peroxidase_I.
DR   InterPro; IPR019794; Peroxidases_AS.
DR   InterPro; IPR019793; Peroxidases_heam-ligand_BS.
DR   PANTHER; PTHR31356:SF35; L-ASCORBATE PEROXIDASE 2, CYTOSOLIC; 1.
DR   PANTHER; PTHR31356; THYLAKOID LUMENAL 29 KDA PROTEIN, CHLOROPLASTIC-RELATED; 1.
DR   Pfam; PF00141; peroxidase; 1.
DR   PRINTS; PR00459; ASPEROXIDASE.
DR   PRINTS; PR00458; PEROXIDASE.
DR   SUPFAM; SSF48113; Heme-dependent peroxidases; 1.
DR   PROSITE; PS00435; PEROXIDASE_1; 1.
DR   PROSITE; PS00436; PEROXIDASE_2; 1.
DR   PROSITE; PS50873; PEROXIDASE_4; 1.
PE   1: Evidence at protein level;
KW   Calcium; Cytoplasm; Heme; Hydrogen peroxide; Iron; Metal-binding;
KW   Oxidoreductase; Peroxidase; Potassium; Reference proteome.
FT   CHAIN           1..251
FT                   /note="L-ascorbate peroxidase 2, cytosolic"
FT                   /id="PRO_0000261322"
FT   ACT_SITE        43
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00297,
FT                   ECO:0000255|PROSITE-ProRule:PRU10012"
FT   BINDING         163
FT                   /ligand="heme b"
FT                   /ligand_id="ChEBI:CHEBI:60344"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00297"
FT   BINDING         164
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250|UniProtKB:P48534"
FT   BINDING         180
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250|UniProtKB:P48534"
FT   BINDING         182
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250|UniProtKB:P48534"
FT   BINDING         185
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250|UniProtKB:P48534"
FT   BINDING         187
FT                   /ligand="K(+)"
FT                   /ligand_id="ChEBI:CHEBI:29103"
FT                   /evidence="ECO:0000250|UniProtKB:P48534"
FT   SITE            39
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00297"
FT   CONFLICT        6
FT                   /note="Y -> F (in Ref. 7; ABE65932)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        231
FT                   /note="F -> S (in Ref. 1; CAA56340 and 2; CAA66925)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   251 AA;  28006 MW;  FFC7F6D82A4EF3E0 CRC64;
     MVKKSYPEVK EEYKKAVQRC KRKLRGLIAE KHCAPIVLRL AWHSAGTFDV KTKTGGPFGT
     IRHPQELAHD ANNGLDIAVR LLDPIKELFP ILSYADFYQL AGVVAVEITG GPEIPFHPGR
     LDKVEPPPEG RLPQATKGVD HLRDVFGRMG LNDKDIVALS GGHTLGRCHK ERSGFEGAWT
     PNPLIFDNSY FKEILSGEKE GLLQLPTDKA LLDDPLFLPF VEKYAADEDA FFEDYTEAHL
     KLSELGFADK E
//