5LC7

Crystal structure of a single chain monellin mutant: E23Q/Q28K/C41S/Y65R-MNEI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Sweeter and stronger: enhancing sweetness and stability of the single chain monellin MNEI through molecular design.

Leone, S.Pica, A.Merlino, A.Sannino, F.Temussi, P.A.Picone, D.

(2016) Sci Rep 6: 34045-34045

  • DOI: 10.1038/srep34045
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Sweet proteins are a family of proteins with no structure or sequence homology, able to elicit a sweet sensation in humans through their interaction with the dimeric T1R2-T1R3 sweet receptor. In particular, monellin and its single chain derivative (M ...

    Sweet proteins are a family of proteins with no structure or sequence homology, able to elicit a sweet sensation in humans through their interaction with the dimeric T1R2-T1R3 sweet receptor. In particular, monellin and its single chain derivative (MNEI) are among the sweetest proteins known to men. Starting from a careful analysis of the surface electrostatic potentials, we have designed new mutants of MNEI with enhanced sweetness. Then, we have included in the most promising variant the stabilising mutation E23Q, obtaining a construct with enhanced performances, which combines extreme sweetness to high, pH-independent, thermal stability. The resulting mutant, with a sweetness threshold of only 0.28 mg/L (25 nM) is the strongest sweetener known to date. All the new proteins have been produced and purified and the structures of the most powerful mutants have been solved by X-ray crystallography. Docking studies have then confirmed the rationale of their interaction with the human sweet receptor, hinting at a previously unpredicted role of plasticity in said interaction.


    Organizational Affiliation

    Dipartimento di Scienze Chimiche, Università di Napoli Federico II, I-80126, Napoli, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Monellin chain B,Monellin chain A
A, B
97Dioscoreophyllum cumminsiiMutation(s): 4 
Find proteins for P02882 (Dioscoreophyllum cumminsii)
Go to UniProtKB:  P02882
Find proteins for P02881 (Dioscoreophyllum cumminsii)
Go to UniProtKB:  P02881
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.198 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 31.480α = 105.27
b = 39.260β = 109.13
c = 43.970γ = 103.96
Software Package:
Software NamePurpose
XDSdata reduction
REFMACrefinement
PHASERphasing
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2016-06-19 
  • Released Date: 2016-10-05 
  • Deposition Author(s): Pica, A., Merlino, A.

Funding OrganizationLocationGrant Number
Fondazione con il SudItalyPDR-10 2011

Revision History 

  • Version 1.0: 2016-10-05
    Type: Initial release