Architecture of the Rix1-Rea1 checkpoint machinery during pre-60S-ribosome remodeling
Architecture of the Rix1-Rea1 checkpoint machinery during pre-60S-ribosome remodeling
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DOI：
10.1038/nsmb.3132
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发表时间：
2016-01-01
影响因子：
16.8
通讯作者：
Hurt, Ed
中科院分区：
文献类型：
--
作者：
Barrio-Garcia, Clara;Thoms, Matthias;Hurt, Ed
核糖体合成由类似 200 个组装因子催化，有助于成熟核糖体的高效生产。在这里，我们确定了含有动力蛋白相关的 550-kDa Real AAA(+) ATPase 和 Rixl 亚复合物的酿酒酵母核质前 60S 颗粒的冷冻电镜结构。该颗粒与其之前的状态（早期的 Arxl 颗粒）不同，有两个大规模的结构重排：5S 核糖核蛋白复合物和中央突起 (CP) rRNA 螺旋的类似 180 度旋转，以及从 5.8S rRNA 3' 端去除“脚”结构。从 Arxl 到 Rixl 颗粒的进展被 Rixl-Real 相互作用的突变扰动所阻止，但不会被显性致死的 Real AAA(+) ATPase 环突变体阻止。重塑后，Rixl 亚复合体和 Real 处于适当的位置，可以感知 CP 的正确结构成熟，从而允许向成熟核糖体单向进展。
Ribosome synthesis is catalyzed by similar to 200 assembly factors, which facilitate efficient production of mature ribosomes. Here, we determined the cryo-EM structure of a Saccharomyces cerevisiae nucleoplasmic pre-60S particle containing the dynein-related 550-kDa Real AAA(+) ATPase and the Rixl subcomplex. This particle differs from its preceding state, the early Arxl particle, by two massive structural rearrangements: an similar to 180 degrees rotation of the 5S ribonucleoprotein complex and the central protuberance (CP) rRNA helices, and the removal of the 'foot' structure from the 3' end of the 5.8S rRNA. Progression from the Arxl to the Rixl particle was blocked by mutational perturbation of the Rixl-Real interaction but not by a dominant-lethal Real AAA(+) ATPase-ring mutant. After remodeling, the Rixl subcomplex and Real become suitably positioned to sense correct structural maturation of the CP, which allows unidirectional progression toward mature ribosomes.