Nop9 binds the central pseudoknot region of 18S rRNA.
Nop9 binds the central pseudoknot region of 18S rRNA.
复制标题
Nop9 结合 18S rRNA 的中央假结区域
DOI：
10.1093/nar/gkw1323
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发表时间：
2017-04-07
影响因子：
14.9
通讯作者：
Ye K
中科院分区：
文献类型：
--
作者：
Wang B;Ye K
Abstract The assembly of eukaryotic ribosomes requires numerous factors that transiently associate with evolving pre-ribosomal particles. The Pumilio repeat-containing protein Nop9 briefly associates with the 90S pre-ribosome during its co-transcriptional assembly. Here, we show that Nop9 specifically binds an 11-nucleotide sequence of 18S rRNA that forms the 3΄ side of the central pseudoknot and helix 28 in the mature subunit. Crystal structures of Nop9 in the free and RNA-bound states reveal a new type of Pumilio repeat protein with a distinct structure, target sequence and RNA-binding mode. Nop9 contains 10 Pumilio repeats arranged into a U-shaped scaffold. The target RNA is recognized by two stretches of repeats in a bipartite manner, and three central bases are unrecognized as a result of the degeneracy of repeats 6 and 7. Our data suggest that Nop9 regulates the folding of 18S rRNA at early assembly stages of 90S.
