RNA-binding proteins are essential for gene regulation and the spatial organization of cells. Here, we report that the yeast ribosome biogenesis factor Loc1p is an intrinsically disordered RNA-binding protein with eight repeating positively charged, unstructured nucleic acid binding (PUN) motifs. While a single of these previously undefined motifs stabilizes folded RNAs, multiple copies strongly cooperate to catalyze RNA folding. In the presence of RNA, these multivalent PUN motifs drive phase separation. Proteome-wide searches in pro- and eukaryotes for proteins with similar arrays of PUN motifs reveal a strong enrichment in RNA-mediated processes and DNA remodeling. Thus, PUN motifs are potentially involved in a large variety of RNA- and DNA-related processes by concentrating them in membraneless organelles. The general function and wide distribution of PUN motifs across species suggest that in an ancient ‘RNA world’ PUN-like motifs may have supported the correct folding of early ribozymes.

中文翻译：

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固有无序的 RNA 结合基序协同催化 RNA 折叠并驱动相分离


RNA 结合蛋白对于基因调控和细胞的空间组织至关重要。在这里，我们报道了酵母核糖体生物发生因子 Loc1p 是一种固有无序的 RNA 结合蛋白，具有八个重复的带正电荷的非结构化核酸结合 （PUN） 基序。虽然这些先前未定义的基序中的单个稳定折叠的 RNA，但多个拷贝强烈合作以催化 RNA 折叠。在 RNA 存在下，这些多价 PUN 基序驱动相分离。在原生生物和真核生物中对具有相似 PUN 基序阵列的蛋白质进行蛋白质组范围搜索，揭示了 RNA 介导的过程和 DNA 重塑的强烈富集。因此，PUN 基序通过集中在无膜细胞器中，可能参与多种 RNA 和 DNA 相关过程。PUN 基序的一般功能和跨物种的广泛分布表明，在古老的“RNA 世界”中，类似 PUN 的基序可能支持早期核酶的正确折叠。