P92947 · MDAR_ARATH
- ProteinMonodehydroascorbate reductase, chloroplastic/mitochondrial
- GeneMDAR5
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids493 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalyzes the conversion of monodehydroascorbate (MDA) to ascorbate, oxidizing NADH in the process. Can also use 2,4,6-trinitrotoluene (TNT) and 1-chloro-2,4-dinitrobenzene (CDNB) as substrates, but not 1-chloro-4-nitrobenzene (CNB).
Miscellaneous
The use of alternative transcription starts causes dual targeting of the same mature MDAR protein to both mitochondria and chloroplast.
Catalytic activity
- H+ + 2 monodehydro-L-ascorbate radical + NADH = 2 L-ascorbate + NAD+
Cofactor
Activity regulation
Redox regulation of the activity by thioredoxin TRXy1.
Biotechnology
The main mechanism for TNT toxicity in plants is the production of superoxide in the mitochondria by MDAR5 with TNT as a substrate. Inactivation of MDAR5 enhance TNT tolerance, thus enabling revegetation and remediation of explosives-contaminated sites.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
522 μM | 2,4,6-trinitrotoluene | |||||
4.1 μM | monodehydroascorbate | |||||
1254 μM | 1-chloro-2,4-dinitrobenzene |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
0.143 mmol/min/mg | with 2,4,6-trinitrotoluene as substrate | ||||
190 mmol/min/mg | with monodehydroascorbate as substrate | ||||
0.96 mmol/min/mg | with 1-chloro-2,4-dinitrobenzene as substrate |
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 68-71 | FAD (UniProtKB | ChEBI) | ||||
Sequence: GGNA | ||||||
Binding site | 95 | FAD (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 102 | FAD (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 107 | FAD (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 201-202 | FAD (UniProtKB | ChEBI) | ||||
Sequence: RE | ||||||
Binding site | 224-230 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: GGYIGME | ||||||
Binding site | 226-230 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: YIGME | ||||||
Binding site | 248 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 254 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 254 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 313 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 313 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 351 | FAD (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 367-368 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: EH | ||||||
Binding site | 367-368 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: EH | ||||||
Binding site | 369 | FAD (UniProtKB | ChEBI) | ||||
Sequence: V | ||||||
Binding site | 373 | L-ascorbate (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 398 | FAD (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 398 | NAD+ (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 398 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 400 | L-ascorbate (UniProtKB | ChEBI) | ||||
Sequence: R |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | chloroplast | |
Cellular Component | chloroplast stroma | |
Cellular Component | mitochondrion | |
Cellular Component | nucleus | |
Cellular Component | stromule | |
Molecular Function | ATP binding | |
Molecular Function | monodehydroascorbate reductase (NADH) activity | |
Biological Process | response to cold |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameMonodehydroascorbate reductase, chloroplastic/mitochondrial
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis
Accessions
- Primary accessionP92947
- Secondary accessions
Proteomes
Organism-specific databases
Genome annotation databases
Subcellular Location
UniProt Annotation
GO Annotation
Isoform MDAR6
Isoform MDAR5
Keywords
- Cellular component
Phenotypes & Variants
Disruption phenotype
No visible phenotype, but enhanced 2,4,6-trinitrotoluene (TNT) tolerance.
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 29 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for transit peptide, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transit peptide | 1-51 | Chloroplast and mitochondrion | ||||
Sequence: MSAVRRVMALASTTLPTKSGLSLWCPSSPSLARRFPARFSPIGSRIASRSL | ||||||
Chain | PRO_0000018621 | 52-493 | Monodehydroascorbate reductase, chloroplastic/mitochondrial | |||
Sequence: VTASFANENREFVIVGGGNAAGYAARTFVENGMADGRLCIVTKEAYAPYERPALTKAYLFPPEKKPARLPGFHTCVGGGGERQTPDWYKEKGIEVIYEDPVAGADFEKQTLTTDAGKQLKYGSLIIATGCTASRFPDKIGGHLPGVHYIREVADADSLIASLGKAKKIVIVGGGYIGMEVAAAAVAWNLDTTIVFPEDQLLQRLFTPSLAQKYEELYRQNGVKFVKGASINNLEAGSDGRVSAVKLADGSTIEADTVVIGIGAKPAIGPFETLAMNKSIGGIQVDGLFRTSTPGIFAIGDVAAFPLKIYDRMTRVEHVDHARRSAQHCVKSLLTAHTDTYDYLPYFYSRVFEYEGSPRKVWWQFFGDNVGETVEVGNFDPKIATFWIESGRLKGVLVESGSPEEFQLLPKLARSQPLVDKAKLASASSVEEALEIAQAALQS |
Proteomic databases
PTM databases
Expression
Gene expression databases
Structure
Sequence & Isoform
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
This entry describes 2 isoforms produced by Alternative promoter usage.
P92947-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- NameMDAR5
- SynonymsPMDAR-L
- Length493
- Mass (Da)53,302
- Last updated2004-07-19 v3
- Checksum44FBF0DE65DA89D7
P92947-2
- NameMDAR6
- SynonymsPMDAR-S
- Differences from canonical
- 1-7: Missing
Computationally mapped potential isoform sequences
There are 2 potential isoforms mapped to this entry
Features
Showing features for alternative sequence, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_011360 | 1-7 | in isoform MDAR6 | |||
Sequence: Missing | ||||||
Sequence conflict | 109 | in Ref. 1; BAA12349 | ||||
Sequence: Y → H |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
D84417 EMBL· GenBank· DDBJ | BAA12349.2 EMBL· GenBank· DDBJ | mRNA | ||
AC010852 EMBL· GenBank· DDBJ | AAG52455.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CP002684 EMBL· GenBank· DDBJ | AEE34168.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CP002684 EMBL· GenBank· DDBJ | AEE34171.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY034934 EMBL· GenBank· DDBJ | AAK59441.1 EMBL· GenBank· DDBJ | mRNA | ||
AY142572 EMBL· GenBank· DDBJ | AAN13141.1 EMBL· GenBank· DDBJ | mRNA | ||
BT000667 EMBL· GenBank· DDBJ | AAN31814.1 EMBL· GenBank· DDBJ | mRNA |