生物谷報(bào)道：谷氨酸轉(zhuǎn)運(yùn)分子（Glutamate transporters）在大腦和周圍神經(jīng)系統(tǒng)中扮演一個(gè)重要角色，利用離子梯度來(lái)在谷氨酸鹽從突觸前神經(jīng)元中釋放之后將其從突觸縫隙中清除掉?，F(xiàn)在,，Yernool等人確定了一種細(xì)菌的谷氨酸鹽運(yùn)輸分子的晶體結(jié)構(gòu)，該分子與人類的谷氨酸鹽運(yùn)輸分子EAAT2有37%的相同點(diǎn),，其晶體結(jié)構(gòu)讓我們清楚地看到了這些運(yùn)輸神經(jīng)傳輸物質(zhì)的分子是如何工作的,。該分子有一個(gè)引人注目的結(jié)構(gòu)：它是一個(gè)簡(jiǎn)單的碗形三聚物，其作用是作為水溶劑的一個(gè)容器,，這個(gè)容器半穿過(guò)細(xì)胞膜,。“碗”的底部有三個(gè)基質(zhì)結(jié)合點(diǎn)，其側(cè)面為發(fā)卡狀的螺旋體,，它們的同步運(yùn)動(dòng)可能是交替接觸細(xì)胞膜兩邊的關(guān)鍵,。

Glutamate transporters are integral membrane proteins that catalyse the concentrative uptake of glutamate from the synapse to intracellular spaces by harnessing pre-existing ion gradients. In the central nervous system glutamate transporters are essential for normal development and function, and are implicated in stroke, epilepsy and neurodegenerative diseases. Here we present the crystal structure of a eukaryotic glutamate transporter homologue from Pyrococcus horikoshii. The transporter is a bowl-shaped trimer with a solvent-filled extracellular basin extending halfway across the membrane bilayer. At the bottom of the basin are three independent binding sites, each cradled by two helical hairpins, reaching from opposite sides of the membrane. We propose that transport of glutamate is achieved by movements of the hairpins that allow alternating access to either side of the membrane.