P83966 (MDARF_CUCSA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Monodehydroascorbate reductase, fruit isozyme Short name=MDAR fruit EC=1.6.5.4 Alternative name(s): Ascorbate free radical reductase fruit Short name=AFR reductase fruit
Organism	Cucumis sativus (Cucumber)
Taxonomic identifier	3659 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › fabids › Cucurbitales › Cucurbitaceae › Benincaseae › Cucumis

Protein attributes

Sequence length	166 AA.
Sequence status	Fragments.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalyzes the conversion of monodehydroascorbate to ascorbate, oxidizing NADH in the process.
Catalytic activity	NADH + 2 monodehydroascorbate = NAD+ + 2 ascorbate. Ref.2
Cofactor	FAD. Ref.2
Post-translational modification	The N-terminus is blocked. Ref.1
Sequence similarities	Belongs to the FAD-dependent oxidoreductase family.
Biophysicochemical properties	Kinetic parameters: KM=4.6 µM for NADH KM=23 µM for NADPH KM=1.4 µM for monodehydroascorbate Vmax=256 µmol/min/mg enzyme for NADH oxidation reaction Vmax=192 µmol/min/mg enzyme for NADPH oxidation reaction pH dependence: Optimum pH is 7-9.

Ontologies

Keywords
Domain	Redox-active center
Ligand	FAD Flavoprotein NAD
Molecular function	Oxidoreductase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Molecular function	monodehydroascorbate reductase (NADH) activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	‹1 – ›166	›166	Monodehydroascorbate reductase, fruit isozyme		PRO_0000209141
Experimental info
	Sequence uncertainty	92	1	L or K Ref.1
	Non-adjacent residues	13 – 14	2
	Non-adjacent residues	32 – 33	2
	Non-adjacent residues	58 – 59	2
	Non-adjacent residues	92 – 93	2
	Non-adjacent residues	128 – 129	2
	Non-adjacent residues	135 – 136	2
	Non-adjacent residues	150 – 151	2
	Non-terminal residue	1	1
	Non-terminal residue	166	1

Sequences

	Sequence		Length	Mass (Da)
	P83966 [UniParc]. Last modified June 7, 2004. Version 1. Checksum: 0816E13BF68A6260	FASTA	166	18,811
	10 20 30 40 50 60 EAVAPYERPA LSKNIFYLRE IADADQLVEA IKLKDGRTLD ADIVVVGVGG RPLVSLFKTS 70 80 90 100 110 120 IPDVYAVGDV ATYPLKLYNE LRRVEHVDHA RLSIEEYDYL PYFYSRTFNL AWQFYGDNVG 130 140 150 160 ETVLFPDNFG TYWIKVVGVF LEGGTPDEYK VARVQPPVES LDQLAK

References

[1]	"cDNA cloning of monodehydroascorbate radical reductase from Cucumber: a high degree of homology in terms of amino acid sequence between this enzyme and bacterial flavoenzymes." Sano S., Asada K. Plant Cell Physiol. 35:425-437(1994) [PubMed: 8055175] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Fruit.
[2]	"Monodehydroascorbate reductase from cucumber is a flavin adenine dinucleotide enzyme." Hossain M.A., Asada K. J. Biol. Chem. 260:12920-12926(1985) [PubMed: 4055727] [Abstract] Cited for: CATALYTIC ACTIVITY, COFACTOR. Tissue: Fruit.

Cross-references

3D structure databases
ProteinModelPortal	P83966.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
ProtoNet	Search...

Entry information

Entry name

MDARF_CUCSA

Accession

Primary (citable) accession number: P83966

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 19, 2004
Last sequence update:	June 7, 2004
Last modified:	September 21, 2011
This is version 35 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program