Characterization of a novel prokaryotic GDP dissociation inhibitor domain from the G protein coupled membrane protein FeoB
Characterization of a novel prokaryotic GDP dissociation inhibitor domain from the G protein coupled membrane protein FeoB
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DOI：
10.1016/j.jmb.2007.11.027
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发表时间：
2008-01-25
影响因子：
5.6
通讯作者：
Unger, Vinzenz M.
中科院分区：
文献类型：
--
作者：
Eng, Edward T.;Jalilian, Amir R.;Unger, Vinzenz M.
FeoB家族膜包埋G蛋白参与原核生物对Fe(II)的高亲和力摄取。在这里，我们报告了FeoB含有一个新的GDP解离抑制因子样结构域，它通过与G蛋白的Switch I区域相互作用而特异性地稳定GDP结合。我们表明，尽管鸟嘌呤核苷酸解离抑制因子(GDI)样结构域具有高度的序列可变性，但物种间GDP结合的稳定性是保守的，并证明了膜嵌入结构域的存在使GDP结合亲和力比仅通过GDI样结构域作用的水平提高了约150倍。据我们所知，这是第一个针对细菌G蛋白偶联膜过程的原核生物GDI的例子。我们的发现表明，细菌对Fe(II)的吸收涉及G蛋白调节途径，这使人想起在高等生物体中发现的信号机制。(C)2007爱思唯尔有限公司。保留所有权利。
The FeoB family of membrane embedded G proteins are involved with high affinity Fe(II) uptake in prokaryotes. Here, we report that FeoB harbors a novel GDP dissociation inhibitor-like domain that specifically stabilizes GDP-binding through an interaction with the switch I region of the G protein. We show that the stabilization of GDP binding is conserved between species despite a high degree of sequence variability in their guanine nucleotide dissociation inhibitor (GDI)-like domains, and demonstrate that the presence of the membrane embedded domain increases GDP-binding affinity roughly 150-fold over the level accomplished by action of the GDI-like domain alone. To our knowledge, this is the first example for a prokaryotic GDI, targeting a bacterial G protein-coupled membrane process. Our findings suggest that Fe(II) uptake in bacteria involves a G protein regulatory pathway reminiscent of signaling mechanisms found in higher-order organisms. (c) 2007 Elsevier Ltd. All rights reserved.