Outer membrane active transport:: Structure of the BtuB:TonB complex
Outer membrane active transport:: Structure of the BtuB:TonB complex
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DOI：
10.1126/science.1127694
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发表时间：
2006-06-02
期刊：
影响因子：
56.9
通讯作者：
Wiener, Michael C.
中科院分区：
文献类型：
--
作者：
Shultis, David D.;Purdy, Michael D.;Wiener, Michael C.
在革兰氏阴性菌中，必需微量营养素穿过外膜的输入需要转运蛋白、穿过内膜的质子的电化学梯度以及将质子动力耦合到外膜转运蛋白的内膜蛋白复合物（ExbB、ExbD、TonB）。内膜蛋白TonB直接结合到转运蛋白的保守区域，称为Ton-box。我们解决了钴胺素转运蛋白BtuB与TonB的C-末端结构域复合的结构。与其在不存在TonB的情况下的构象相反，Ton-box形成β链，其被募集到TonB的现有B片层，这与运输的机械拉动模型一致。
In Gram-negative bacteria, the import of essential micronutrients across the outer membrane requires a transporter, an electrochemical gradient of protons across the inner membrane, and an inner membrane protein complex (ExbB, ExbD, TonB) that couples the proton-motive force to the outer membrane transporter. The inner membrane protein TonB binds directly to a conserved region, called the Ton-box, of the transporter. We solved the structure of the cobalamin transporter BtuB in complex with the C-terminal domain of TonB. In contrast to its conformations in the absence of TonB, the Ton-box forms a beta strand that is recruited to the existing b sheet of TonB, which is consistent with a mechanical pulling model of transport.