3VHF

plant thaumatin I at pH 8.0


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.39 Å
  • R-Value Free: 0.168 
  • R-Value Work: 0.148 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Atomic structure of the sweet-tasting protein thaumatin I at pH 8.0 reveals the large disulfide-rich region in domain II to be sensitive to a pH change

Masuda, T.Ohta, K.Mikami, B.Kitabatake, N.Tani, F.

(2012) Biochem.Biophys.Res.Commun. 419: 72-76

  • DOI: 10.1016/j.bbrc.2012.01.129
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Thaumatin, an intensely sweet-tasting plant protein, elicits a sweet taste at 50 nM. Although the sweetness remains when thaumatin is heated at 80 °C for 4h under acid conditions, it rapidly declines when heating at a pH above 6.5. To clarify the str ...

    Thaumatin, an intensely sweet-tasting plant protein, elicits a sweet taste at 50 nM. Although the sweetness remains when thaumatin is heated at 80 °C for 4h under acid conditions, it rapidly declines when heating at a pH above 6.5. To clarify the structural difference at high pH, the atomic structure of a recombinant thaumatin I at pH 8.0 was determined at a resolution of 1.0Å. Comparison to the crystal structure of thaumatin at pH 7.3 and 7.0 revealed the root-mean square deviation value of a Cα atom to be substantially greater in the large disulfide-rich region of domain II, especially residues 154-164, suggesting that a loop region in domain II to be affected by solvent conditions. Furthermore, B-factors of Lys137, Lys163, and Lys187 were significantly affected by pH change, suggesting that a striking increase in the mobility of these lysine residues, which could facilitate a reaction with a free sulfhydryl residue produced via the β-elimination of disulfide bonds by heating at a pH above 7.0. The increase in mobility of lysine residues as well as a loop region in domain II might play an important role in the heat-induced aggregation of thaumatin above pH 7.0.


    Organizational Affiliation

    Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan. t2masuda@kais.kyoto-u.ac.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Thaumatin I
A
207Thaumatococcus danielliiMutation(s): 0 
Find proteins for P02883 (Thaumatococcus daniellii)
Go to UniProtKB:  P02883
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.39 Å
  • R-Value Free: 0.168 
  • R-Value Work: 0.148 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 43.688α = 90.00
b = 63.653β = 90.00
c = 71.743γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data scaling
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-05-16
    Type: Initial release