7F8S

Pennisetum glaucum (Pearl millet) dehydroascorbate reductase (DHAR) with catalytic cysteine (Cy20) in sulphenic and sulfinic acid forms.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.63 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Comparative kinetic analysis of ascorbate (Vitamin-C) recycling dehydroascorbate reductases from plants and humans.

Das, B.K.Kumar, A.Sreekumar, S.N.Ponraj, K.Gadave, K.Kumar, S.Murali Achary, V.M.Ray, P.Reddy, M.K.Arockiasamy, A.

(2021) Biochem Biophys Res Commun 591: 110-117

  • DOI: https://doi.org/10.1016/j.bbrc.2021.12.103
  • Primary Citation of Related Structures:  
    7F8R, 7F8S

  • PubMed Abstract: 

    Ascorbate is an important cellular antioxidant that gets readily oxidized to dehydroascorbate (DHA). Recycling of DHA is therefore paramount in the maintenance of cellular homeostasis and preventing oxidative stress. Dehydroascorbate reductases (DHARs), in conjunction with glutathione (GSH), carry out this vital process in eukaryotes, among which plant DHARs have garnered considerable attention. A detailed kinetic analysis of plant DHARs relative to their human counterparts is, however, lacking. Chloride intracellular channels (HsCLICs) are close homologs of plant DHARs, recently demonstrated to share their enzymatic activity. This study reports the highest turnover rate for a plant DHAR from stress adapted Pennisetum glaucum (PgDHAR). In comparison, HsCLICs 1, 3, and 4 reduced DHA at a significantly lower rate. We further show that the catalytic cysteine from both homologs was susceptible to varying degrees of oxidation, validated by crystal structures and mass-spectrometry. Our findings may have broader implications on crop improvement using pearl millet DHAR vis-à-vis discovery of cancer therapeutics targeting Vitamin-C recycling capability of human CLICs.


  • Organizational Affiliation

    Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Southern California Institute for Research and Education, Veterans Affairs Long Beach Health Care System, 5901 E. 7th Street Long Beach, CA, 90822, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Dehydroascorbate reductase233Cenchrus americanusMutation(s): 0 
EC: 1.8.5.1
UniProt
Find proteins for U5XYA0 (Cenchrus americanus)
Explore U5XYA0 
Go to UniProtKB:  U5XYA0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupU5XYA0
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Dehydroascorbate reductase233Cenchrus americanusMutation(s): 0 
EC: 1.8.5.1
UniProt
Find proteins for U5XYA0 (Cenchrus americanus)
Explore U5XYA0 
Go to UniProtKB:  U5XYA0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupU5XYA0
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A]
D [auth A]
E [auth A]
F [auth A]
G [auth A]
C [auth A],
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth B],
I [auth B],
J [auth B],
K [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
Modified Residues  2 Unique
IDChains TypeFormula2D DiagramParent
CSO
Query on CSO
A
L-PEPTIDE LINKINGC3 H7 N O3 SCYS
CSD
Query on CSD
B
L-PEPTIDE LINKINGC3 H7 N O4 SCYS
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 97.561α = 90
b = 97.561β = 90
c = 109.064γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
HKL-2000data reduction
HKL-2000data scaling
PDB_EXTRACTdata extraction
BALBESphasing
Cootmodel building

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Department of Biotechnology (DBT, India)IndiaBT/PR28080/BID/7/836/2018
Department of Biotechnology (DBT, India)IndiaBT/PR28766/BRB/10/1701/2018
Department of Science & Technology (DST, India)IndiaEMR/2017/005066

Revision History  (Full details and data files)

  • Version 1.0: 2022-01-19
    Type: Initial release
  • Version 1.1: 2023-11-29
    Changes: Data collection, Refinement description
  • Version 1.2: 2024-10-09
    Changes: Structure summary