ジャーナル: Nature / 年: 2020 タイトル: Structural basis of ligand recognition and self-activation of orphan GPR52. 著者: Xi Lin / Mingyue Li / Niandong Wang / Yiran Wu / Zhipu Luo / Shimeng Guo / Gye-Won Han / Shaobai Li / Yang Yue / Xiaohu Wei / Xin Xie / Yong Chen / Suwen Zhao / Jian Wu / Ming Lei / Fei Xu / 要旨: GPR52 is a class-A orphan G-protein-coupled receptor that is highly expressed in the brain and represents a promising therapeutic target for the treatment of Huntington's disease and several ...GPR52 is a class-A orphan G-protein-coupled receptor that is highly expressed in the brain and represents a promising therapeutic target for the treatment of Huntington's disease and several psychiatric disorders. Pathological malfunction of GPR52 signalling occurs primarily through the heterotrimeric G protein, but it is unclear how GPR52 and G couple for signal transduction and whether a native ligand or other activating input is required. Here we present the high-resolution structures of human GPR52 in three states: a ligand-free state, a G-coupled self-activation state and a potential allosteric ligand-bound state. Together, our structures reveal that extracellular loop 2 occupies the orthosteric binding pocket and operates as a built-in agonist, conferring an intrinsically high level of basal activity to GPR52. A fully active state is achieved when G is coupled to GPR52 in the absence of an external agonist. The receptor also features a side pocket for ligand binding. These insights into the structure and function of GPR52 could improve our understanding of other self-activated GPCRs, enable the identification of endogenous and tool ligands, and guide drug discovery efforts that target GPR52.
プロトコル: SINGLE WAVELENGTH / 単色(M)・ラウエ(L): M / 散乱光タイプ: x-ray
放射波長
波長: 1 Å / 相対比: 1
反射
解像度: 2.9→50 Å / Num. obs: 18312 / % possible obs: 97.6 % / 冗長度: 9.2 % / CC1/2: 0.991 / Rmerge(I) obs: 0.235 / Net I/σ(I): 11.8
反射 シェル
解像度: 2.9→3 Å / Rmerge(I) obs: 2.748 / Mean I/σ(I) obs: 0.98 / Num. unique obs: 1810 / CC1/2: 0.4
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解析
ソフトウェア
名称
バージョン
分類
REFMAC
5.8.0253
精密化
HKL-2000
データ削減
HKL-2000
データスケーリング
PHASER
位相決定
精密化
構造決定の手法: 分子置換 開始モデル: Rosetta modelling 解像度: 2.9→28.43 Å / Cor.coef. Fo:Fc: 0.917 / Cor.coef. Fo:Fc free: 0.915 / SU B: 21.26 / SU ML: 0.367 / 交差検証法: THROUGHOUT / ESU R: 0.811 / ESU R Free: 0.364 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS There are some unknown densities located near N5 atom of FMN in a chain. This was not been modelled.
Rfactor
反射数
%反射
Selection details
Rfree
0.26677
912
5.2 %
RANDOM
Rwork
0.24427
-
-
-
obs
0.24548
16462
95.56 %
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溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK