Institute of Molecular and Cell Biology, University of Tartu, Riia 23b, 51010 Tartu, Estonia.
Int J Mol Sci. 2023 Feb 4;24(4):3128. doi: 10.3390/ijms24043128.
Bacterial ribosomes contain over 50 ribosome core proteins (r-proteins). Tens of non-ribosomal proteins bind to ribosomes to promote various steps of translation or suppress protein synthesis during ribosome hibernation. This study sets out to determine how translation activity is regulated during the prolonged stationary phase. Here, we report the protein composition of ribosomes during the stationary phase. According to quantitative mass-spectrometry analysis, ribosome core proteins bL31B and bL36B are present during the late log and first days of the stationary phase and are replaced by corresponding A paralogs later in the prolonged stationary phase. Ribosome hibernation factors Rmf, Hpf, RaiA, and Sra are bound to the ribosomes during the onset and a few first days of the stationary phase when translation is strongly suppressed. In the prolonged stationary phase, a decrease in ribosome concentration is accompanied by an increase in translation and association of translation factors with simultaneous dissociation of ribosome hibernating factors. The dynamics of ribosome-associated proteins partially explain the changes in translation activity during the stationary phase.
细菌核糖体包含超过 50 种核糖体核心蛋白（r 蛋白）。数十种非核糖体蛋白与核糖体结合，以促进翻译的各个步骤，或在核糖体休眠期间抑制蛋白质合成。本研究旨在确定在长时间的静止期，翻译活性是如何被调控的。在这里，我们报告了静止期核糖体的蛋白质组成。根据定量质谱分析，核糖体核心蛋白 bL31B 和 bL36B 在对数后期和静止期的头几天存在，并且在延长的静止期后期被相应的 A 同源物取代。核糖体休眠因子 Rmf、Hpf、RaiA 和 Sra 在翻译被强烈抑制时与核糖体结合，在静止期开始和最初几天。在延长的静止期，核糖体浓度的降低伴随着翻译的增加以及翻译因子与核糖体休眠因子的同时解离。核糖体相关蛋白的动态部分解释了在静止期翻译活性的变化。
