8ZXV | pdb_00008zxv

sweet protein MNEI-Mut 6-4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.43 Å
  • R-Value Free: 
    0.203 (Depositor), 0.204 (DCC) 
  • R-Value Work: 
    0.171 (Depositor), 0.172 (DCC) 
  • R-Value Observed: 
    0.173 (Depositor) 

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

Structural Basis for the Exceptional Thermal Stability of the Boiling-Resistant Sweet Protein MNEI.

You, T.Shi, S.Chen, C.Li, J.Xu, J.Ma, M.Zhu, P.Qi, T.Dong, T.Wang, Y.Ye, S.Liu, S.

(2025) J Agric Food Chem 73: 15959-15966

  • DOI: https://doi.org/10.1021/acs.jafc.4c13158
  • Primary Citation of Related Structures:  
    8ZXJ, 8ZXT, 8ZXV, 8ZXY

  • PubMed Abstract: 

    Monellin, known as the sweetest protein, encounters limitations in the food industry due to its poor thermal stability, prompting modifications to enhance its thermal stability. In our previous work, we utilized Python Rosetta to screen multiple designs, successfully constructing four superstable MNEI (single-chain monellin) mutants that can maintain their sweetness at temperatures up to 100 °C. However, the precise mechanism of increased thermal stability remains unclear. To elucidate the mechanism, we determine the high-resolution crystal structures of four superstable mutants and conduct a comprehensive structural analysis combined with molecular dynamics simulations in our study. Our findings indicate that introduction of mutation sites enhances interactions with surrounding residues in some flexible loop regions, particularly in loop K25-R31, potentially stabilizing flexible regions and may contribute to enhancing the rigidity of the global structure. This study provides a direction for further advancement in mutant modifications.


  • Organizational Affiliation
    • Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Monellin chain B,Monellin chain A
A, B
96Dioscoreophyllum cumminsiiMutation(s): 6 
UniProt
Find proteins for P02881 (Dioscoreophyllum cumminsii)
Explore P02881 
Go to UniProtKB:  P02881
Find proteins for P02882 (Dioscoreophyllum cumminsii)
Explore P02882 
Go to UniProtKB:  P02882
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP02881P02882
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.43 Å
  • R-Value Free:  0.203 (Depositor), 0.204 (DCC) 
  • R-Value Work:  0.171 (Depositor), 0.172 (DCC) 
  • R-Value Observed: 0.173 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.318α = 90
b = 58.56β = 90
c = 66.139γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXmodel building
HKL-3000phasing
HKL-3000data scaling

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2025-06-18
    Type: Initial release
  • Version 1.1: 2025-06-25
    Changes: Database references
  • Version 1.2: 2025-07-09
    Changes: Database references