Transport mechanism of a bacterial homologue of glutamate transporters.
Transport mechanism of a bacterial homologue of glutamate transporters.
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作者：
谷氨酸转运蛋白是一种完整的膜蛋白，通过利用预先存在的电化学梯度离子的能量，催化神经递质谷氨酸从突触间隙向上摄取到神经胶质细胞和神经细胞的细胞质。该反应的关键是转运蛋白在向外和向内两种状态之间的构象转换，底物结合部位分别从细胞外空间和细胞质进入。在这里，我们描述了谷氨酸转运体的细菌同系物GltPh的双半胱氨酸突变体的晶体结构，该突变体通过半胱氨酸交联被捕获在内向状态。结合先前确定的GltPh外向状态的晶体结构，交联突变体的结构使我们能够提出一种分子机制，通过这种机制，GltPh和哺乳动物的谷氨酸转运体介导钠偶联底物的摄取。
Glutamate transporters are integral membrane proteins that catalyze a thermodynamically uphill uptake of the neurotransmitter glutamate from the synaptic cleft into the cytoplasm of glial and neuronal cells by harnessing the energy of pre-existing electrochemical gradients of ions. The linchpin of the reaction is the conformational transition of the transporters between outward and inward facing states, in which the substrate binding sites are accessible from the extracellular space and the cytoplasm respectively. Here we describe a crystal structure of a double cysteine mutant of a bacterial homologue of glutamate transporters, GltPh, which is trapped in the inward facing state by cysteine cross-linking. Together with the previously determined crystal structure of GltPh in the outward facing state, the structure of the cross-linked mutant allows us to propose a molecular mechanism, by which GltPh and, by analogy, mammalian glutamate transporters, mediate sodium-coupled substrate uptake.
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影响因子：
15
作者：
Dieckmann, GR;McRorie, DK;Pecoraro, VL
通讯作者：
Pecoraro, VL
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
5.6
作者：
Groeneveld, Maarten;Slotboom, Dirk-Jan
通讯作者：
Slotboom, Dirk-Jan
影响因子：
5.3
作者：
Koch, Hans Peter;Brown, Ronald Lane;Larsson, Hans Peter
通讯作者：
Larsson, Hans Peter
影响因子：
5.3
作者：
Leary, Gregory P.;Stone, Emily F.;Kavanaugh, Michael P.
通讯作者：
Kavanaugh, Michael P.