Yeast eIF4G1 interacts with RNA binding proteins (RBPs) like Pab1 and Pub1 affecting its function in translation initiation and stress granules formation. We present an NMR and SAXS study of the intrinsically disordered region of eIF4G1, eIF4G1_1-249, and its interactions with Pub1 and Pab1. The conformational ensemble of eIF4G1_1-249 shows an α-helix within the BOX3 conserved element and a dynamic network of fuzzy π-π and π-cation interactions involving arginine and aromatic residues. The Pab1 RRM2 domain interacts with eIF4G1 BOX3, the canonical interaction site, but also with BOX2, a conserved element of unknown function to date. In contrast, the Pub1 RRM3 domain interacts with the RNA1-1 and BOX1 regions of eIF4G1. Mixtures of Pub1, Pab1 and eIF4G1 form micrometer-size protein condensates that require the presence of the eIF4G1 BOX1 element. These homotypic interactions suggest a double key mechanism of eIF4G1 regulation, important for understanding the architecture of stress granule cores.

中文翻译：

---

eIF4G1，Pub1和Pab1之间的多价相互作用驱动蛋白质冷凝物的形成

酵母eIF4G1与RNA结合蛋白（RBP）相互作用，例如Pab1和Pub1，影响其在翻译起始和应激颗粒形成中的功能。我们目前对eIF4G1，eIF4G1 _1-249的固有无序区及其与Pub1和Pab1的相互作用进行NMR和SAXS研究。eIF4G1 _1-249的构象整体图1显示了BOX3保守元素内的α-螺旋和涉及精氨酸和芳族残基的模糊π-π和π-阳离子相互作用的动态网络。Pab1 RRM2域与eIF4G1 BOX3（规范的相互作用位点）相互作用，但也与BOX2（迄今为止未知功能的保守元素）相互作用。相反，Pub1 RRM3域与eIF4G1的RNA1-1和BOX1区相互作用。Pub1，Pab1和eIF4G1的混合物形成了微米级的蛋白质缩合物，需要存在eIF4G1 BOX1元素。这些同型相互作用表明eIF4G1调节的双键机制，对于理解应力颗粒核心的体系结构很重要。