ID MDAR_ARATH Reviewed; 493 AA. AC P92947; Q94CE2; Q9CAK5; DT 19-JUL-2004, integrated into UniProtKB/Swiss-Prot. DT 19-JUL-2004, sequence version 3. DT 02-SEP-2026, entry version 166. DE RecName: Full=Monodehydroascorbate reductase, chloroplastic/mitochondrial {ECO:0000303|PubMed:16146528}; DE EC=1.6.5.4 {ECO:0000269|PubMed:26339024}; DE AltName: Full=Monodehydroascorbate reductase 5, mitochondrial {ECO:0000303|PubMed:16146528}; DE Short=AtMDAR5 {ECO:0000303|PubMed:16146528}; DE AltName: Full=Monodehydroascorbate reductase 6, chloroplastic {ECO:0000303|PubMed:16146528}; DE Short=AtMDAR6 {ECO:0000303|PubMed:16146528}; DE Flags: Precursor; GN Name=MDAR5 {ECO:0000303|PubMed:16146528}; GN Synonyms=MDAR6 {ECO:0000303|PubMed:16146528}, MDHAR6 GN {ECO:0000303|PubMed:26339024}, PMDAR-L {ECO:0000303|PubMed:12154132}, GN PMDAR-S {ECO:0000303|PubMed:12154132}; GN OrderedLocusNames=At1g63940 {ECO:0000312|Araport:AT1G63940}; GN ORFNames=T12P18.4 {ECO:0000312|EMBL:AAG52455.1}; 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 [MRNA] (ISOFORM MDAR5). RA Hossain A., Miyake C., Aoki H., Matsuo M., Yamaguchi T., Nishimura M., RA Ida S., Asada K.; RT "cDNA of chloroplastic monodehydroascorbate radical reductase from RT Arabidopsis thaliana."; RL Submitted (APR-1996) to the EMBL/GenBank/DDBJ databases. RN [2] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=cv. Columbia; RX PubMed=11130712; DOI=10.1038/35048500; RA Theologis A., Ecker J.R., Palm C.J., Federspiel N.A., Kaul S., White O., RA Alonso J., Altafi H., Araujo R., Bowman C.L., Brooks S.Y., Buehler E., RA Chan A., Chao Q., Chen H., Cheuk R.F., Chin C.W., Chung M.K., Conn L., RA Conway A.B., Conway A.R., Creasy T.H., Dewar K., Dunn P., Etgu P., RA Feldblyum T.V., Feng J.-D., Fong B., Fujii C.Y., Gill J.E., Goldsmith A.D., RA Haas B., Hansen N.F., Hughes B., Huizar L., Hunter J.L., Jenkins J., RA Johnson-Hopson C., Khan S., Khaykin E., Kim C.J., Koo H.L., RA Kremenetskaia I., Kurtz D.B., Kwan A., Lam B., Langin-Hooper S., Lee A., RA Lee J.M., Lenz C.A., Li J.H., Li Y.-P., Lin X., Liu S.X., Liu Z.A., RA Luros J.S., Maiti R., Marziali A., Militscher J., Miranda M., Nguyen M., RA Nierman W.C., Osborne B.I., Pai G., Peterson J., Pham P.K., Rizzo M., RA Rooney T., Rowley D., Sakano H., Salzberg S.L., Schwartz J.R., Shinn P., RA Southwick A.M., Sun H., Tallon L.J., Tambunga G., Toriumi M.J., Town C.D., RA Utterback T., Van Aken S., Vaysberg M., Vysotskaia V.S., Walker M., Wu D., RA Yu G., Fraser C.M., Venter J.C., Davis R.W.; RT "Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana."; RL Nature 408:816-820(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 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 [5] RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORMS MDAR5 AND MDAR6). 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 [6] RP ALTERNATIVE SPLICING (ISOFORMS MDAR5 AND MDAR6), AND SUBCELLULAR RP LOCATION(ISOFORMS MDAR5 AND MDAR6). RX PubMed=12154132; DOI=10.1093/pcp/pcf103; RA Obara K., Sumi K., Fukuda H.; RT "The use of multiple transcription starts causes the dual targeting of RT Arabidopsis putative monodehydroascorbate reductase to both mitochondria RT and chloroplasts."; RL Plant Cell Physiol. 43:697-705(2002). RN [7] RP GENE FAMILY, AND NOMENCLATURE. RX PubMed=16146528; DOI=10.1111/j.1365-313x.2005.02503.x; RA Lisenbee C.S., Lingard M.J., Trelease R.N.; RT "Arabidopsis peroxisomes possess functionally redundant membrane and matrix RT isoforms of monodehydroascorbate reductase."; RL Plant J. 43:900-914(2005). RN [8] RP INTERACTION WITH TRXY, AND ACTIVITY REGULATION. RX PubMed=20405473; DOI=10.1002/pmic.200900835; RA Marchand C.H., Vanacker H., Collin V., Issakidis-Bourguet E., RA Marechal P.L., Decottignies P.; RT "Thioredoxin targets in Arabidopsis roots."; RL Proteomics 10:2418-2428(2010). RN [9] RP IDENTIFICATION BY MASS SPECTROMETRY, AND CLEAVAGE OF TRANSIT PEPTIDE AFTER RP LEU-51. RX PubMed=25732537; DOI=10.1093/jxb/erv064; RA Carrie C., Venne A.S., Zahedi R.P., Soll J.; RT "Identification of cleavage sites and substrate proteins for two RT mitochondrial intermediate peptidases in Arabidopsis thaliana."; RL J. Exp. Bot. 66:2691-2708(2015). RN [10] RP FUNCTION, CATALYTIC ACTIVITY, SUBCELLULAR LOCATION, BIOTECHNOLOGY, RP DISRUPTION PHENOTYPE, AND BIOPHYSICOCHEMICAL PROPERTIES. RX PubMed=26339024; DOI=10.1126/science.aab3472; RA Johnston E.J., Rylott E.L., Beynon E., Lorenz A., Chechik V., Bruce N.C.; RT "Monodehydroascorbate reductase mediates TNT toxicity in plants."; RL Science 349:1072-1075(2015). CC -!- FUNCTION: Catalyzes the conversion of monodehydroascorbate (MDA) to CC ascorbate, oxidizing NADH in the process (PubMed:26339024). Mediates CC phytotoxicity of 2,4,6-trinitrotoluene (TNT), an explosive and CC environmental pollutant, by reducing TNT and forming a nitro radical CC that spontaneously reacts with atmospheric oxygen, generating reactive CC superoxide (PubMed:26339024). Can also use 1-chloro-2,4-dinitrobenzene CC (CDNB) as substrate, but not 1-chloro-4-nitrobenzene (CNB) CC (PubMed:26339024). {ECO:0000269|PubMed:26339024}. CC -!- CATALYTIC ACTIVITY: CC Reaction=2 monodehydro-L-ascorbate radical + NADH + H(+) = 2 L- CC ascorbate + NAD(+); Xref=Rhea:RHEA:14581, ChEBI:CHEBI:15378, CC ChEBI:CHEBI:38290, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945, CC ChEBI:CHEBI:59513; EC=1.6.5.4; CC Evidence={ECO:0000269|PubMed:26339024}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:14582; CC Evidence={ECO:0000269|PubMed:26339024}; CC -!- CATALYTIC ACTIVITY: CC Reaction=2,4,6-trinitrotoluene + NADH = 2,4,6-trinitrotoluene radical + CC e(-) + NAD(+); Xref=Rhea:RHEA:80511, ChEBI:CHEBI:10545, CC ChEBI:CHEBI:46053, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945, CC ChEBI:CHEBI:231530; Evidence={ECO:0000269|PubMed:26339024}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:80512; CC Evidence={ECO:0000269|PubMed:26339024}; CC -!- COFACTOR: CC Name=FAD; Xref=ChEBI:CHEBI:57692; CC Evidence={ECO:0000250|UniProtKB:Q9S926}; CC -!- ACTIVITY REGULATION: Redox regulation of the activity by thioredoxin CC TRXy1. {ECO:0000269|PubMed:20405473}. CC -!- BIOPHYSICOCHEMICAL PROPERTIES: CC Kinetic parameters: CC KM=522 uM for 2,4,6-trinitrotoluene {ECO:0000269|PubMed:26339024}; CC KM=4.1 uM for monodehydroascorbate {ECO:0000269|PubMed:26339024}; CC KM=1254 uM for 1-chloro-2,4-dinitrobenzene CC {ECO:0000269|PubMed:26339024}; CC Vmax=0.143 mmol/min/mg enzyme with 2,4,6-trinitrotoluene as substrate CC {ECO:0000269|PubMed:26339024}; CC Vmax=109 mmol/min/mg enzyme with monodehydroascorbate as substrate CC {ECO:0000269|PubMed:26339024}; CC Vmax=0.96 mmol/min/mg enzyme with 1-chloro-2,4-dinitrobenzene as CC substrate {ECO:0000269|PubMed:26339024}; CC -!- SUBUNIT: Interacts in vitro with TRXy. {ECO:0000269|PubMed:20405473}. CC -!- SUBCELLULAR LOCATION: [Isoform MDAR6]: Plastid, chloroplast CC {ECO:0000269|PubMed:12154132}. CC -!- SUBCELLULAR LOCATION: [Isoform MDAR5]: Mitochondrion CC {ECO:0000269|PubMed:12154132, ECO:0000305|PubMed:25732537}. CC -!- ALTERNATIVE PRODUCTS: CC Event=Alternative promoter usage; Named isoforms=2; CC Name=MDAR5; Synonyms=PMDAR-L; CC IsoId=P92947-1; Sequence=Displayed; CC Name=MDAR6; Synonyms=PMDAR-S; CC IsoId=P92947-2; Sequence=VSP_011360; CC -!- DISRUPTION PHENOTYPE: No visible phenotype under normal conditions, but CC enhanced 2,4,6-trinitrotoluene (TNT) tolerance. CC {ECO:0000269|PubMed:26339024}. CC -!- BIOTECHNOLOGY: The main mechanism for TNT toxicity in plants is the CC production of superoxide in the mitochondria by MDAR5 with TNT as a CC substrate. Inactivation of MDAR5 enhance TNT tolerance, thus enabling CC revegetation and remediation of explosives-contaminated sites. CC {ECO:0000269|PubMed:26339024}. CC -!- MISCELLANEOUS: The use of alternative transcription starts causes dual CC targeting of the same mature MDAR protein to both mitochondria and CC chloroplast. {ECO:0000269|PubMed:12154132}. CC -!- SIMILARITY: Belongs to the FAD-dependent oxidoreductase family. CC {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; D84417; BAA12349.2; -; mRNA. DR EMBL; AC010852; AAG52455.1; -; Genomic_DNA. DR EMBL; CP002684; AEE34168.1; -; Genomic_DNA. DR EMBL; CP002684; AEE34171.1; -; Genomic_DNA. DR EMBL; OZ408683; CAO7031992.1; -; Genomic_DNA. DR EMBL; AY034934; AAK59441.1; -; mRNA. DR EMBL; AY142572; AAN13141.1; -; mRNA. DR EMBL; BT000667; AAN31814.1; -; mRNA. DR PIR; E96664; E96664. DR RefSeq; NP_564818.1; NM_105067.4. [P92947-2] DR RefSeq; NP_849839.1; NM_179508.3. [P92947-1] DR AlphaFoldDB; P92947; -. DR SMR; P92947; -. DR BioGRID; 27918; 16. DR FunCoup; P92947; 1026. DR IntAct; P92947; 3. DR STRING; 3702.P92947; -. DR iPTMnet; P92947; -. DR PaxDb; 3702-P92947; -. DR ProteomicsDB; 238765; -. [P92947-1] DR GeneID; 842697; -. DR KEGG; ath:AT1G63940; -. DR Araport; AT1G63940; -. DR TAIR; AT1G63940; MDAR6. DR eggNOG; KOG1336; Eukaryota. DR InParanoid; P92947; -. DR PhylomeDB; P92947; -. DR BioCyc; ARA:AT1G63940-MONOMER; -. DR BRENDA; 1.6.5.4; 399. DR SABIO-RK; P92947; -. DR CD-CODE; 4299E36E; Nucleolus. DR PRO; PR:P92947; -. DR Proteomes; UP000006548; Chromosome 1. DR ExpressionAtlas; P92947; baseline and differential. DR GO; GO:0009507; C:chloroplast; HDA:TAIR. DR GO; GO:0009570; C:chloroplast stroma; HDA:TAIR. DR GO; GO:0005739; C:mitochondrion; IDA:TAIR. DR GO; GO:0005634; C:nucleus; HDA:TAIR. DR GO; GO:0010319; C:stromule; IDA:TAIR. DR GO; GO:0005524; F:ATP binding; HDA:TAIR. DR GO; GO:0016656; F:monodehydroascorbate reductase (NADH) activity; EXP:UniProtKB. DR GO; GO:0009409; P:response to cold; IEP:TAIR. DR FunFam; 3.30.390.30:FF:000018; Monodehydroascorbate reductase; 1. DR Gene3D; 3.30.390.30; -; 1. DR Gene3D; 3.50.50.60; FAD/NAD(P)-binding domain; 2. DR InterPro; IPR050446; FAD-oxidoreductase/Apoptosis. DR InterPro; IPR036188; FAD/NAD-bd_sf. DR InterPro; IPR023753; FAD/NAD-binding_dom. DR InterPro; IPR016156; FAD/NAD-linked_Rdtase_dimer_sf. DR InterPro; IPR048618; MDHAR3-like_C. DR PANTHER; PTHR43557; APOPTOSIS-INDUCING FACTOR 1; 1. DR PANTHER; PTHR43557:SF6; MONODEHYDROASCORBATE REDUCTASE, CHLOROPLASTIC_MITOCHONDRIAL; 1. DR Pfam; PF21791; MDHAR3-like_C; 1. DR Pfam; PF07992; Pyr_redox_2; 1. DR PRINTS; PR00368; FADPNR. DR PRINTS; PR00411; PNDRDTASEI. DR SUPFAM; SSF51905; FAD/NAD(P)-binding domain; 2. PE 1: Evidence at protein level; KW Alternative promoter usage; Chloroplast; FAD; Flavoprotein; Mitochondrion; KW NAD; NADP; Oxidoreductase; Plastid; Redox-active center; KW Reference proteome; Transit peptide. FT TRANSIT 1..51 FT /note="Chloroplast and mitochondrion" FT /evidence="ECO:0000305|PubMed:25732537" FT CHAIN 52..493 FT /note="Monodehydroascorbate reductase, FT chloroplastic/mitochondrial" FT /id="PRO_0000018621" FT BINDING 68..71 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 95 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 102 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 107 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 201..202 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 224..230 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 226..230 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 248 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 254 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 254 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 313 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 313 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 351 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 367..368 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 367..368 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 369 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 373 FT /ligand="L-ascorbate" FT /ligand_id="ChEBI:CHEBI:38290" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 398 FT /ligand="FAD" FT /ligand_id="ChEBI:CHEBI:57692" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 398 FT /ligand="NAD(+)" FT /ligand_id="ChEBI:CHEBI:57540" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 398 FT /ligand="NADP(+)" FT /ligand_id="ChEBI:CHEBI:58349" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT BINDING 400 FT /ligand="L-ascorbate" FT /ligand_id="ChEBI:CHEBI:38290" FT /evidence="ECO:0000250|UniProtKB:Q652L6" FT VAR_SEQ 1..7 FT /note="Missing (in isoform MDAR6)" FT /evidence="ECO:0000303|PubMed:14593172" FT /id="VSP_011360" FT CONFLICT 109 FT /note="Y -> H (in Ref. 1; BAA12349)" FT /evidence="ECO:0000305" SQ SEQUENCE 493 AA; 53302 MW; 44FBF0DE65DA89D7 CRC64; MSAVRRVMAL ASTTLPTKSG LSLWCPSSPS LARRFPARFS PIGSRIASRS LVTASFANEN REFVIVGGGN AAGYAARTFV ENGMADGRLC IVTKEAYAPY ERPALTKAYL FPPEKKPARL PGFHTCVGGG GERQTPDWYK EKGIEVIYED PVAGADFEKQ TLTTDAGKQL KYGSLIIATG CTASRFPDKI GGHLPGVHYI REVADADSLI ASLGKAKKIV IVGGGYIGME VAAAAVAWNL DTTIVFPEDQ LLQRLFTPSL AQKYEELYRQ NGVKFVKGAS INNLEAGSDG RVSAVKLADG STIEADTVVI GIGAKPAIGP FETLAMNKSI GGIQVDGLFR TSTPGIFAIG DVAAFPLKIY DRMTRVEHVD HARRSAQHCV KSLLTAHTDT YDYLPYFYSR VFEYEGSPRK VWWQFFGDNV GETVEVGNFD PKIATFWIES GRLKGVLVES GSPEEFQLLP KLARSQPLVD KAKLASASSV EEALEIAQAA LQS //