The RRM domain of human fused in sarcoma protein reveals a non-canonical nucleic acid binding site

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1832

Article

Liu, Xuehui¹  Niu, Chunyan²  Ren, Jintao^2,3  Zhang, Jiayu^4,5  Xie, Xiaodong³  Zhu, Haining^4,5  Feng, Wei¹  Gong, Weimin² 

[1] Chinese Acad Sci, Inst Biophys, Natl Lab Biomacromol, Beijing 100101, Peoples R China

[2] Chinese Acad Sci, Inst Biophys, Lab Noncoding RNA, Beijing 100101, Peoples R China

[3] Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Gansu, Peoples R China

[4] Univ Kentucky, Coll Med, Dept Mol & Cellular Biochem, Lexington, KY 40536 USA

[5] Univ Kentucky, Coll Med, Struct Biol Ctr, Lexington, KY 40536 USA

关键词: Fused in sarcoma;    RNA recognition motif;    Amyotrophic lateral sclerosis;    Nucleic acid binding;    NMR;    Surface plasmon resonance;   

DOI  :  10.1016/j.bbadis.2012.11.012

来源: Elsevier

【 摘 要 】

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.

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