Transmembrane signaling across the ligand-gated FhuA receptor: Crystal structures of free and ferrichrome-bound states reveal allosteric changes
Transmembrane signaling across the ligand-gated FhuA receptor: Crystal structures of free and ferrichrome-bound states reveal allosteric changes
复制标题
DOI：
10.1016/s0092-8674(00)81700-6
复制
发表时间：
1998-12-11
期刊：
影响因子：
64.5
通讯作者：
Moras, D
中科院分区：
文献类型：
--
作者：
Locher, KP;Rees, B;Moras, D
FhuA蛋白促进配体门控转运铁色素结合铁穿过大肠杆菌外膜。2.7埃分辨率的X射线分析揭示了在存在和不存在铁色素的情况下两种不同的构象。单体蛋白由中空的22股反平行β桶（残基160-714）组成，其被塞子（残基19-159）阻塞。铁色素的结合位点是细胞表面附近的芳香口袋，在与配体结合时发生微小变化。这些传播和放大整个插头，最终导致在周质面的蛋白质构象有很大的不同。我们的研究结果揭示了信号传递的机制，并提出了能量转导的Tons复合物如何感知配体结合。
FhuA protein facilitates ligand-gated transport of ferrichrome-bound iron across Escherichia coli outer membranes. X-ray analysis at 2.7 Angstrom resolution reveals two distinct conformations in the presence and absence of ferrichrome. The monomeric protein consists of a hollow, 22-stranded, antiparallel beta barrel (residues 160-714), which is obstructed by a plug (residues 19-159). The binding site of ferrichrome, an aromatic pocket near the cell surface, undergoes minor changes upon association with the ligand. These are propagated and amplified across the plug, eventually resulting in substantially different protein conformations at the periplasmic face. Our findings reveal the mechanism of signal transmission and suggest how the energy-transducing Tons complex senses ligand binding.