3ALD

Crystal structure of sweet-tasting protein Thaumatin I at 1.10 A

Summary for 3ALD

• Entry DOI: 10.2210/pdb3ald/pdb
• Related: 3AL7
• Descriptor: Thaumatin I, L(+)-TARTARIC ACID, GLYCEROL, ... (4 entities in total)
• Functional Keywords: thaumatin, sweet-tasting protein, plant protein
• Biological source: Thaumatococcus daniellii
• Total number of polymer chains: 1
• Total formula weight: 22896.59

Authors

Masuda, T.,Mikami, B.,Kitabatake, N. (deposition date: 2010-07-29, release date: 2011-06-08, Last modification date: 2011-11-02)

Primary citation

Masuda, T.,Ohta, K.,Mikami, B.,Kitabatake, N.
High-resolution structure of the recombinant sweet-tasting protein thaumatin I
Acta Crystallogr.,Sect.F, 67:652-658, 2011

PubMed Abstract: Thaumatin, an intensely sweet-tasting plant protein, elicits a sweet taste at a concentration of 50 nM. The crystal structure of a recombinant form of thaumatin I produced in the yeast Pichia pastoris has been determined to a resolution of 1.1 Å. The model was refined with anisotropic B parameters and riding H atoms. A comparison of the diffraction data and refinement statistics for recombinant thaumatin I with those for plant thaumatin I revealed no significant differences in the diffraction data. The R values for recombinant thaumatin I and plant thaumatin I (F(o) > 4σ) were 9.11% and 9.91%, respectively, indicating the final model to be of good quality. Notably, the electron-density maps around Asn46 and Ser63, which differ between thaumatin variants, were significantly improved. Furthermore, a number of H atoms became visible in an OMIT map and could be assigned. The high-quality structure of recombinant thaumatin with H atoms should provide details about sweetness determinants in thaumatin and provide valuable insights into the mechanism of its interaction with taste receptors.

PubMed: 21636903
DOI: 10.1107/S174430911101373X

Experimental method

X-RAY DIFFRACTION (1.1 Å)