Disruption of transcription-translation coordination in Escherichia coli leads to premature transcriptional termination
Disruption of transcription-translation coordination in Escherichia coli leads to premature transcriptional termination
复制标题
大肠杆菌转录-翻译协调的破坏导致转录过早终止
DOI：
10.1038/s41564-019-0543-1
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发表时间：
2019
影响因子：
28.3
通讯作者：
Xiongfeng Dai
中科院分区：
文献类型：
--
作者：
Manlu Zhu;Matteo Mori;Terence hwa;Xiongfeng Dai
转录和翻译之间的紧密协调对于维持细菌中基因表达的完整性至关重要，但细菌如何协调这两个过程仍不清楚。近年来，RNA聚合酶与核糖体之间可能的直接物理偶联已被深入研究。在这里，我们定量表征转录动力学ofEscherichia coli在不同的生长条件。转录和翻译延伸保持协调在各种营养条件下，如前所述。然而，转录延伸不受抗生素的影响，减缓翻译延伸。这一结果也是通过引入使转录与翻译完全分离的无义突变而发现的。因此，我们的数据提供了直接的证据，翻译是不需要保持转录延伸的速度。在转录和翻译是分离的情况下，我们的研究提供了定量表征的结果提前转录终止（PTT）的过程。PTT介导的极性所引起的抑制靶向抗生素实质上影响了几个长操纵子中的基因的协调表达，有助于这些抗生素的关键生理效应。我们的研究结果还表明，在正常生长条件下，转录和翻译延伸之间的协调是由鸟苷四磷酸实现的模型。
Tight coordination between transcription and translation is crucial to maintaining the integrity of gene expression in bacteria, yet how bacteria manage to coordinate these two processes remains unclear. Possible direct physical coupling between the RNA polymerase and ribosome has been thoroughly investigated in recent years. Here, we quantitatively characterize the transcriptional kinetics ofEscherichia coliunder different growth conditions. Transcriptional and translational elongation remain coordinated under various nutrient conditions, as previously reported. However, transcriptional elongation was not affected under antibiotics that slowed down translational elongation. This result was also found by introducing nonsense mutation that completely dissociated transcription from translation. Our data thus provide direct evidence that translation is not required to maintain the speed of transcriptional elongation. In cases where transcription and translation are dissociated, our study provides quantitative characterization of the resulting process of premature transcriptional termination (PTT). PTT-mediated polarity caused by translation-targeting antibiotics substantially affected the coordinated expression of genes in several long operons, contributing to the key physiological effects of these antibiotics. Our results also suggest a model in which the coordination between transcriptional and translational elongation under normal growth conditions is implemented by guanosine tetraphosphate.