Structures of the human and Drosophila 80S ribosome

摘要

几种细菌和核糖体的结构在过去十年已经发rn表，但我们却不得不等待那些要大得多、复杂rn得多的后生动物核糖体的基因组。现在，rnRolarld Beckmarln及其同事发表了果蝇和人类rn80S核糖体的冷电子显微镜结构。它们的复杂rn性的增加似乎也导致了更多的结构层次。这些rn结构将促使人们去做实验，来了解这些额外结rn构层次在功能上和演化上的重要性。%Protein synthesis in all cells is carried out by macromolecular machines called ribosomes. Although the structures of prokaryotic, yeast and protist ribosomes have been determined, the more complex molecular architecture of metazoan 80S ribosomes has so far remained elusive. Here we present structures of Drosophila melanogaster and Homo sapiens 80S ribosomes in complex with the translation factor eEF2, E-site transfer RNA and Stml-like proteins, based on high-resolution cryo-electron-microscopy density maps. These structures not only illustrate the co-evolution of metazoan-specific ribosomal RNA with ribosomal proteins but also reveal the presence of two additional structural layers in metazoan ribosomes, a well-ordered inner layer covered by a flexible RNA outer layer. The human and Drosophila ribosome structures will provide the basis for more detailed structural, biochemical and genetic experiments.