Ribosome biogenesis, involving processing/assembly of rRNAs and r-proteins is a vital process. In mitochondria, ribosomal small subunit comprises 15S rRNA (15S). While the 15S 5′-end processing uses Ccm1p and Pet127p, the mechanisms of the 3′-end processing remain unclear. We reveal involvement of Rmd9p in safeguarding/processing 15S 3′-end. Rmd9p deficiency results in a cleavage at a position 183 nucleotides upstream of 15S 3′-end, and in the loss of the 3′-minor domain. Rmd9p binds to the sequences in the 3'-end region of 15S, and a genetic interaction between and indicates that Rmd9p regulates/limits mtEXO activity during the 3′-end spacer processing.

中文翻译：

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Rmd9p 在酿酒酵母线粒体 15S rRNA 3′端加工中的作用

核糖体生物发生，涉及 rRNA 和 r 蛋白的加工/组装，是一个至关重要的过程。在线粒体中，核糖体小亚基包含 15S rRNA (15S)。虽然 15S 5' 端加工使用 Ccm1p 和 Pet127p，但 3' 端加工机制仍不清楚。我们揭示了 Rmd9p 参与保护/处理 15S 3'-末端。 Rmd9p 缺陷会导致 15S 3'-末端上游 183 个核苷酸位置处的裂解，并导致 3'-次要结构域的丢失。 Rmd9p 与 15S 3' 端区域的序列结合，并且 和 之间的遗传相互作用表明 Rmd9p 在 3' 端间隔区加工过程中调节/限制 mtEXO 活性。