The RRM domain of human fused in sarcoma protein reveals a non-canonical nucleic acid binding site
The RRM domain of human fused in sarcoma protein reveals a non-canonical nucleic acid binding site
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人类肉瘤蛋白中融合的 RRM 结构域揭示了一个非规范的核酸结合位点
DOI：
10.1016/j.bbadis.2012.11.012
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发表时间：
2013-02-01
影响因子：
6.2
通讯作者：
Gong, Weimin
中科院分区：
文献类型：
--
作者：
Liu, Xuehui;Niu, Chunyan;Gong, Weimin
融合肉瘤（FUS）参与了许多RNA代谢过程。FUS和另一种RNA结合蛋白TDP-43与肌萎缩侧索硬化症（ALS）有关。FUS的RNA识别基序（RRM）的性质尚不清楚，对其进行表征具有重要意义。更重要的是，据报道，消除TDP-43的RRM结构域的RNA结合能力可以抑制TDP-43在果蝇中的神经毒性。FUS-RRM的序列与典型的RRM有很大的不同，但通过NMR测定的FUS-RRM的溶液结构显示出与其他RRM相似的整体折叠。我们发现，FUS-RRM直接结合到RNA和DNA的结合亲和力是在微摩尔范围内，通过表面等离子体共振和NMR滴定测量。FUS-RRM中的核酸结合口袋显著扭曲，因为几个关键的芳香族残基缺失。在FUS-RRM中的一个特别带正电荷的环直接参与RNA/DNA结合，这在其他RRM中没有发现。取代独特KK环中的赖氨酸残基会损害核酸结合并改变FUS亚细胞定位。结果提供了深入了解FUS-RRM的核酸结合特性及其与ALS的潜在相关性。(C)2012 Elsevier B. V.保留所有权利。
Fused in sarcoma (FUS) is involved in many processes of RNA metabolism. FUS and another RNA binding protein, TDP-43, are implicated in amyotrophic lateral sclerosis (ALS). It is significant to characterize the RNA recognition motif (RRM) of FUS as its nucleic acid binding properties are unclear. More importantly, abolishing the RNA binding ability of the RRM domain of TDP43 was reported to suppress the neurotoxicity of TDP-43 in Drosophila. The sequence of FUS-RRM varies significantly from canonical RRMs, but the solution structure of FUS-RRM determined by NMR showed a similar overall folding as other RRMs. We found that FUS-RRM directly bound to RNA and DNA and the binding affinity was in the micromolar range as measured by surface plasmon resonance and NMR titration. The nucleic acid binding pocket in FUS-RRM is significantly distorted since several critical aromatic residues are missing. An exceptionally positively charged loop in FUS-RRM, which is not found in other RRMs, is directly involved in the RNA/DNA binding. Substituting the lysine residues in the unique KK loop impaired the nucleic acid binding and altered FUS subcellular localization. The results provide insights into the nucleic acid binding properties of FUS-RRM and its potential relevance to ALS. (C) 2012 Elsevier B.V. All rights reserved.