The role of the ribosome in the regulation of gene expression has come into increased focus. It is proposed that ribosomes are catalytic engines capable of changing their protein composition in response to environmental stimuli. Time‐resolved cryo‐electron microscopy (cryo‐EM) techniques are employed to identify quantitative changes in the protein composition and structure of the Saccharomyces cerevisiae 80S ribosomes after shifting the carbon source from glucose to glycerol. Using cryo‐EM combined with the computational classification approach, it is found that a fraction of the yeast cells’ 80S ribosomes lack ribosomal proteins at the entrance and exit sites for tRNAs, including uL16(RPL10), eS1(RPS1), uS11(RPS14A/B), and eS26(RPS26A/B). This fraction increased after a change from glucose to glycerol medium. The quantitative structural analysis supports the hypothesis that ribosomes are dynamic complexes that alter their composition in response to changes in growth or environmental conditions.

中文翻译：

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响应碳源变化的酿酒酵母 80S 核糖体蛋白组成的时间分辨冷冻电镜研究

核糖体在基因表达调控中的作用越来越受到关注。有人提出，核糖体是能够响应环境刺激而改变其蛋白质组成的催化引擎。时间分辨冷冻电子显微镜 (cryo-EM) 技术用于鉴定酿酒酵母蛋白质组成和结构的定量变化将碳源从葡萄糖转移到甘油后的 80S 核糖体。使用cryo-EM结合计算分类方法，发现酵母细胞的一部分80S核糖体在tRNA的入口和出口位点缺乏核糖体蛋白，包括uL16(RPL10)、eS1(RPS1)、uS11(RPS14A) /B) 和 eS26(RPS26A/B)。从葡萄糖培养基变为甘油培养基后，该分数增加。定量结构分析支持以下假设：核糖体是动态复合物，可根据生长或环境条件的变化改变其组成。