KOPRI Repository

Structure and catalytic mechanism of monodehydroascorbate reductase, MDHAR, from Oryza sativa L. japonica

Cited 14 time in wos
Cited 16 time in scopus
Metadata Downloads

Full metadata record

DC FieldValueLanguage
dc.contributor.authorPark, Ae Kyung-
dc.contributor.authorKim, Han-Woo-
dc.contributor.authorLee, Jun Hyuck-
dc.contributor.authorYoon, Ho-Sung-
dc.contributor.authorYul-Ho Kim-
dc.contributor.authorKim, Young-Saeng-
dc.contributor.authorPark, Hyun-
dc.contributor.authorShin, Seung Chul-
dc.contributor.authorRoh, Soo Jung-
dc.contributor.authorLee, Chang Woo-
dc.contributor.authorJeon, Byung Wook-
dc.contributor.authorDo, Hackwon-
dc.contributor.authorKim, Il-Sup-
dc.description.abstractAscorbic acid (AsA) maintains redox homeostasis by scavenging reactive oxygen species from prokaryotes to eukaryotes, especially plants. The enzyme monodehydroascorbate reductase (MDHAR) regenerates AsA by catalysing the reduction of monodehydroascorbate, using NADH or NADPH as an electron donor. The detailed recycling mechanism of MDHAR remains unclear due to lack of structural information. Here, we present the crystal structures of MDHAR in the presence of cofactors, nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+), and complexed with AsA as well as its analogue, isoascorbic acid (ISD). The overall structure of MDHAR is similar to other iron-sulphur protein reductases, except for a unique long loop of 63?80 residues, which seems to be essential in forming the active site pocket. From the structural analysis and structure-guided point mutations, we found that the Arg320 residue plays a major substrate binding role, and the Tyr349 residue mediates electron transfer from NAD(P)H to bound substrate via FAD. The enzymatic activity of MDHAR favours NADH as an electron donor over NADPH. Our results show, for the first time, structural insights into this preference. The MDHAR-ISD complex structure revealed an alternative binding conformation of ISD, compared with the MDHAR-AsA complex. This implies a broad substrate (antioxidant) specificity and resulting greater protective ability of MDHAR.-
dc.titleStructure and catalytic mechanism of monodehydroascorbate reductase, MDHAR, from Oryza sativa L. japonica-
dc.title.alternativeOryzasativa L. japonica 유래의 monodehydroascorbatereductase 구조와 효소반응 기작-
dc.identifier.bibliographicCitationPark, Ae Kyung, et al. 2016. "Structure and catalytic mechanism of monodehydroascorbate reductase, MDHAR, from Oryza sativa L. japonica". <em>SCIENTIFIC REPORTS</em>, 6(33903): 1-10.-
dc.citation.titleSCIENTIFIC REPORTS-
dc.description.jcrRateJCR 2014:8.771-
dc.subject.keywordascobate recycling-
dc.subject.keywordascorbic acid-
dc.subject.keywordcrystal structure-
dc.subject.keywordisoascorbic acid-
dc.subject.keywordmonodehydroascorbate reductase-
dc.subject.keywordreactive oxygen species-
Appears in Collections  
2014-2016, Antarctic Organisms: Cold-Adaptation Mechanism and Its Application (14-16) / Park; Hyun
Files in This Item
General Conditions
      ROMEO Green
    Can archive pre-print and post-print or publisher's version/PDF
      ROMEO Blue
    Can archive post-print (ie final draft post-refereeing) or publisher's version/PDF
      ROMEO Yellow
    Can archive pre-print (ie pre-refereeing)
      ROMEO White
    Archiving not formally supported

    Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.