NMR Structure of a Heterodimeric SAM:SAM Complex: Characterization and Manipulation of EphA2 Binding Reveal New Cellular Functions of SHIP2
NMR Structure of a Heterodimeric SAM:SAM Complex: Characterization and Manipulation of EphA2 Binding Reveal New Cellular Functions of SHIP2
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DOI：
10.1016/j.str.2011.11.013
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发表时间：
2012-01-11
期刊：
影响因子：
5.7
通讯作者：
Buck, Matthias
中科院分区：
文献类型：
--
作者：
Lee, Hyeong J.;Hota, Prasanta K.;Buck, Matthias
蛋白质间相互作用的无菌α基序（SAM）存在于200多种蛋白质中，但其相互作用的结构基础才刚刚变得清晰。在这里，我们通过使用来自化学位移扰动、NOE和RDC实验的NMR限制来解析EphA 2-SHIP 2 SAM：SAM异二聚体复合物的结构。蛋白质表面之间的特异性接触与以前的模型和其他SAM：SAM复合物显著不同。分子动力学和对接模拟表明，在复杂的交替，更高的能量构象的波动。界面表明EphA家族成员与SHIP 2 SAM结合，而EphB成员可能不结合;相应地，我们证明了EphA 1与SHIP 2结合，但EphB 2与SHIP 2结合。设计了结合SHIP 2的EphB 2 SAM的变体。在SHIP 2结合中受损的突变体EphA 2的功能表征揭示了SHIP 2在抑制配体诱导的EphA 2活化和促进受体协调的趋化细胞迁移中的两个先前未被认识的功能。
The sterile alpha motif (SAM) for protein-protein interactions is encountered in over 200 proteins, but the structural basis for its interactions is just becoming clear. Here we solved the structure of the EphA2-SHIP2 SAM:SAM heterodimeric complex by use of NMR restraints from chemical shift perturbations, NOE and RDC experiments. Specific contacts between the protein surfaces differ significantly from a previous model and other SAM:SAM complexes. Molecular dynamics and docking simulations indicate fluctuations in the complex toward alternate, higher energy conformations. The interface suggests that EphA family members bind to SHIP2 SAM, whereas EphB members may not; correspondingly, we demonstrate binding of EphA1, but not of EphB2, to SHIP2. A variant of EphB2 SAM was designed that binds SHIP2. Functional characterization of a mutant EphA2 compromised in SHIP2 binding reveals two previously unrecognized functions of SHIP2 in suppressing ligand-induced activation of EphA2 and in promoting receptor coordinated chemotactic cell migration.