Direct interaction between EFL1 and SBDS is mediated by an intrinsically disordered insertion domain
Direct interaction between EFL1 and SBDS is mediated by an intrinsically disordered insertion domain
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DOI：
10.1016/j.bbrc.2013.12.143
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发表时间：
2014-01-24
影响因子：
3.1
通讯作者：
Yao, Min
中科院分区：
文献类型：
--
作者：
Asano, Nozomi;Atsuumi, Haruka;Yao, Min
抗结合因子Tif6 （eIF6）被延伸因子样1 （EFL1）和Shwachman-Bodian-Diamond综合征（SBDS）蛋白去除是核糖体成熟后期的关键步骤。虽然已知EFL1具有受SBDS刺激的GTPase活性，但它们如何协同触发Tif6与核糖体的分离仍有待阐明。本研究采用粒径排除色谱法、凝胶移位法和等温滴定量热法（ITC）分析了EFL1与SBDS的相互作用。结果表明，EFL1与SBDS直接相互作用。利用结构域截断突变体进行的ITC实验表明，EFL1与SBDS的相互作用受EFL1的插入结构域和SBDS的II-III结构域控制。圆二色光谱结果表明，在没有SBDS的情况下，EFL1的插入结构域具有随机结构，而在ITC上观察到的不利熵变表明，EFL1的插入结构域具有固定的构象，并与SBDS结合形成络合物。基于这些观察结果以及之前的报道，我们提出了EFL1和SBDS在核糖体成熟中的作用。(C) 2014爱思唯尔公司版权所有。
Removal of anti-association factor, Tif6 (eIF6), by elongation factor-like 1 (EFL1) and Shwachman-Bodian-Diamond syndrome (SBDS) protein is a critical step in the late stage of ribosome maturation. Although EFL1 is known to have GTPase activity that is stimulated by SBDS, how they cooperatively trigger dissociation of Tif6 from the ribosome remains to be elucidated. In the present study, the interaction between EFL1 and SBDS was analyzed by size exclusion chromatography, gel shift assay, and isothermal titration calorimetry (ITC). The results showed that EFL1 interacted directly with SBDS. ITC experiments using domain-truncated mutants showed that the interaction between EFL1 and SBDS is governed by the insertion domain of EFL1 and domains II-III of SBDS. Circular dichroism spectroscopy showed that the insertion domain of EFL1 has a random structure in the absence of SBDS, whereas the disadvantageous entropy change observed on ITC suggested a fixed conformation coupled with complex formation with SBDS. Based on these observations together with those reported previously, we propose roles of EFL1 and SBDS in ribosomal maturation. (C) 2014 Elsevier Inc. All rights reserved.