Architecture of the large subunit of the mammalian mitochondrial ribosome
Architecture of the large subunit of the mammalian mitochondrial ribosome
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DOI：
10.1038/nature12890
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发表时间：
2014-01-23
期刊：
影响因子：
64.8
通讯作者：
Ban, Nenad
中科院分区：
文献类型：
--
作者：
Greber, Basil J.;Boehringer, Daniel;Ban, Nenad
线粒体核糖体合成许多在线粒体基因组上编码的高度疏水蛋白，线粒体是真核细胞中负责通过氧化磷酸化进行能量转换的细胞器。哺乳动物线粒体中的核糖体在其整个进化过程中经历了巨大的结构变化，包括核糖体RNA缩短和获得哺乳动物特异性核糖体蛋白。在这里，我们提出的39S大亚基的猪线粒体核糖体的三维结构确定的冷冻电子显微镜在4.9埃分辨率。结合化学交联和质谱实验的数据，该结构揭示了近原子分辨率下39S亚基的独特特征，并提供了对多肽出口位点结构的详细了解。线粒体核糖体的这一区域与其细菌对应物相比已被显著重塑，为呼吸链的高度疏水蛋白质组分的合成和膜插入提供了专门的平台。
Mitochondrial ribosomes synthesize a number of highly hydrophobic proteins encoded on the genome of mitochondria, the organelles in eukaryotic cells that are responsible for energy conversion by oxidative phosphorylation. The ribosomes in mammalian mitochondria have undergone massive structural changes throughout their evolution, including ribosomal RNA shortening and acquisition of mitochondria-specific ribosomal proteins. Here we present the three-dimensional structure of the 39S large subunit of the porcine mitochondrial ribosome determined by cryo-electron microscopy at 4.9 angstrom resolution. The structure, combined with data from chemical crosslinking and mass spectrometry experiments, reveals the unique features of the 39S subunit at near-atomic resolution and provides detailed insight into the architecture of the polypeptide exit site. This region of the mitochondrial ribosome has been considerably remodelled compared to its bacterial counterpart, providing a specialized platform for the synthesis and membrane insertion of the highly hydrophobic protein components of the respiratory chain.