A potential protein-RNA recognition event along the RISC-loading pathway from the structure of A. aeolicus Argonaute with externally bound siRNA.
A potential protein-RNA recognition event along the RISC-loading pathway from the structure of A. aeolicus Argonaute with externally bound siRNA.
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DOI：
10.1016/j.str.2006.08.009
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发表时间：
2006-10
期刊：
影响因子：
5.7
通讯作者：
Yu-Ren Yuan;Y. Pei;Hong-Ying Chen;T. Tuschl;D. Patel
中科院分区：
文献类型：
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作者：
Yu-Ren Yuan;Y. Pei;Hong-Ying Chen;T. Tuschl;D. Patel
Argonaute蛋白是rna诱导沉默复合体（RISC）的关键成分。它们提供了与小干扰RNA （siRNA）引导链识别和随后的引导链介导的互补mrna切割相关的结构和催化功能。我们报道了与aquifex aeolicusArgonaute （Aa-Ago）结合的22-mer和26-mer siRNA的3.0 Å晶体结构，其中siRNA的一个2 nt 3 '突出插入位于双叶Aa-Ago结构的含paz的叶的外表面的空腔。第一个突出的核苷酸堆积在酪氨酸环上，而第二个突出的核苷酸与中间的糖-磷酸主链一起插入预先形成的表面空腔。对aa - ago与5-碘标记的单链siRNA和siRNA双链的光化学交联研究为这种外部结合的siRNA- aa - ago复合物提供了支持。结构和生化数据一起提供了与risc加载途径潜在相关的蛋白质- rna识别事件的见解。
Argonaute proteins are key components of the RNA-induced silencing complex (RISC). They provide both architectural and catalytic functionalities associated with small interfering RNA (siRNA) guide strand recognition and subsequent guide strand-mediated cleavage of complementary mRNAs. We report on the 3.0 Å crystal structures of 22-mer and 26-mer siRNAs bound toAquifex aeolicusArgonaute (Aa-Ago), where one 2 nt 3′ overhang of the siRNA inserts into a cavity positioned on the outer surface of the PAZ-containing lobe of the bilobalAa-Ago architecture. The first overhang nucleotide stacks over a tyrosine ring, while the second overhang nucleotide, together with the intervening sugar-phosphate backbone, inserts into a preformed surface cavity. Photochemical crosslinking studies onAa-Ago with 5-iodoU-labeled single-stranded siRNA and siRNA duplex provide support for this externally bound siRNA-Aa-Ago complex. The structure and biochemical data together provide insights into a protein-RNA recognition event potentially associated with the RISC-loading pathway.