3ALD

High-resolution structure of the recombinant sweet-tasting protein thaumatin I

(2011) Acta Crystallogr Sect F Struct Biol Cryst Commun 67: 652-658

• PubMed: 21636903 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1107/S174430911101373X
• Primary Citation of Related Structures:  
  3AL7, 3ALD


• 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.

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Organizational Affiliation: 

Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, Japan. [email protected]