8JZ8

Subatomic structure of orthorhombic thaumatin at 0.89 Angstroms

8JZ8 の概要

• エントリーDOI: 10.2210/pdb8jz8/pdb
• 分子名称: Thaumatin I, DI(HYDROXYETHYL)ETHER (3 entities in total)
• 機能のキーワード: thaumatin, sweet-tasting protein, plant protein
• 由来する生物種: Thaumatococcus daniellii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 22546.40

構造登録者

Masuda, T.,Suzuki, M.,Yamasaki, M.,Mikami, B. (登録日: 2023-07-04, 公開日: 2024-05-15, 最終更新日: 2024-10-30)

主引用文献

Masuda, T.,Suzuki, M.,Yamasaki, M.,Mikami, B.
Subatomic structure of orthorhombic thaumatin at 0.89 angstrom reveals that highly flexible conformations are crucial for thaumatin sweetness.
Biochem.Biophys.Res.Commun., 703:149601-149601, 2024

PubMed Abstract: Thaumatin is a sweet-tasting protein that elicits a sweet taste at a threshold of approximately 50 nM. Structure-sweetness relationships in thaumatin suggest that the basicity of two amino acids residues, Arg82 and Lys67, are particularly responsible for sweetness. Using tetragonal crystals, our structural analysis suggested that flexible sidechain conformations of these two residues play an important role in sweetness. However, in tetragonal crystals, Arg82 is adjacent to symmetry-related residues, and its flexibility is relatively restrained by the crystal packing. To reduce and diminish these symmetry-related effects, orthorhombic crystals were prepared, and their structures were successfully determined at a resolution of 0.89 Å. Within the orthorhombic lattice, two alternative conformations were more clearly visible at Lys67 than in a tetragonal system. Interestingly, for the first time, three alternative conformations at Arg82 were only found in an orthorhombic system. These results suggest the importance of flexible conformations in sweetness determinants. Such subtle structural variations might serve to adjust the complementarity of the electrostatic potentials of sweet receptors, thereby eliciting the potent sweet taste of thaumatin.

PubMed: 38364680
DOI: 10.1016/j.bbrc.2024.149601

実験手法

X-RAY DIFFRACTION (0.89 Å)