PDBsum entry 3al7

Plant protein

PDB id: 3al7

Contents

Protein chain

207 a.a.

Ligands

TLA ×2

GOL ×4

Waters ×498

PDB id:

3al7

Name:

Plant protein

Title:

Recombinant thaumatin i at 1.1 a

Structure:

Thaumatin i. Chain: a. Synonym: sweet-tasting protein. Engineered: yes

Source:

Thaumatococcus daniellii. Organism_taxid: 4621. Expressed in: pichia pastoris. Expression_system_taxid: 4922.

Resolution:

1.10Å R-factor: 0.108 R-free: 0.135

Authors:

T.Masuda,B.Mikami,N.Kitabatake

Key ref:

T.Masuda et al. (2011). High-resolution structure of the recombinant sweet-tasting protein thaumatin I. Acta Crystallogr Sect F Struct Biol Cryst Commun, 67, 652-658. PubMed id: 21636903 DOI: 10.1107/S174430911101373X

Date:

27-Jul-10 Release date: 08-Jun-11

Protein chain

P02883  (THM1_THADA) -  Thaumatin I from Thaumatococcus daniellii

Seq: 235 a.a.

Struc: 207 a.a.

DOI no: 10.1107/S174430911101373X

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

PubMed id: 21636903

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

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

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.