Crystal structure of rhodopsin: A G protein-coupled receptor
Crystal structure of rhodopsin: A G protein-coupled receptor
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DOI：
10.1126/science.289.5480.739
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发表时间：
2000-08-04
期刊：
影响因子：
56.9
通讯作者：
Miyano, M
中科院分区：
文献类型：
--
作者：
Palczewski, K;Kumasaka, T;Miyano, M
异三聚体鸟嘌呤核苷酸结合蛋白(G蛋白)偶联受体(GPCRs)对各种不同的外界刺激做出反应，激活G蛋白。GPCRs有许多共同的结构特征，包括由六个不同长度的环连接的七个跨膜α螺旋。我们从2.8埃分辨率的衍射数据中确定了视紫红质的结构。胞外区的高度组织化结构，包括保守的二硫键，构成了七螺旋跨膜基序排列的基础。基态发色团，Il-顺式-视网膜，以非活性构象持有蛋白质的跨膜区。发色团与一簇关键残基的相互作用决定了最大吸收波长。视紫红质之间的这些相互作用的变化促进了颜色辨别。鉴定了一组残基，这些残基介导了跨膜螺旋和细胞质表面之间的相互作用，C蛋白在那里发生激活，这也表明在光激活时可能发生了结构变化。
Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) respond to a variety of different external stimuli and activate G proteins. GPCRs share many structural features, including a bundle of seven transmembrane alpha helices connected by six Loops of varying Lengths. We determined the structure of rhodopsin from diffraction data extending to 2.8 angstroms resolution. The highly organized structure in the extracellular region, including a conserved disulfide bridge, forms a basis for the arrangement of the seven-helix transmembrane motif. The ground-state chromophore, Il-cis-retinal, holds the transmembrane region of the protein in the inactive conformation. Interactions of the chromophore with a cluster of key residues determine the wavelength of the maximum absorption. Changes in these interactions among rhodopsins facilitate color discrimination. Identification of a set of residues that mediate interactions between the transmembrane helices and the cytoplasmic surface, where C-protein activation occurs, also suggests a possible structural change upon photoactivation.