TRANSLATION ACTIVATES THE PAUSED TRANSCRIPTION COMPLEX AND RESTORES TRANSCRIPTION OF THE TRP OPERON LEADER REGION
TRANSLATION ACTIVATES THE PAUSED TRANSCRIPTION COMPLEX AND RESTORES TRANSCRIPTION OF THE TRP OPERON LEADER REGION
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DOI：
10.1073/pnas.82.14.4663
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
YANOFSKY, C
中科院分区：
文献类型：
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作者：
LANDICK, R;CAREY, J;YANOFSKY, C
有人认为，在大肠杆菌色氨酸(Trp)操纵子的前导区暂停的RNA聚合酶负责转录和翻译的同步，这是衰减控制所必需的。利用体外转录/翻译耦合系统研究Trp前导肽的合成对Trp前导区RNA聚合酶停顿的影响。使用大肠杆菌和粘质沙雷氏菌的野生型和翻译缺陷Trp前导模板，并相对于终止前导转录本的合成来量化暂停RNA合成和暂停复合体释放(激活)。观察到，当前导区域的突变或翻译抑制剂卡苏霉素或氯霉素的加入减少了前导转录本的翻译时，Trp前导区域的停顿时间延长。用S-30从一株翻译前导转录中色氨酸密码子效率低下的突变株中提取的实验表明，核糖体移动到这些密码子上也释放了暂停的转录复合体。这些发现表明，暂停的色氨酸前导转录复合体在前导肽编码区的核糖体运动中释放后恢复转录。这一释放将促进对衰减控制至关重要的转录和翻译的耦合。
It was proposed that RNA polymerase pausing in the leader region of the tryptophan (trp) operon of Escherichia coli is responsible for the synchronization of transcription and translation essential to attenuation control. An in vitro coupled transcription/translation system is used to study the effect of trp leader peptide synthesis on RNA polymerase pausing in the trp leader region. Wild-type and translation-defective trp leader templates of E. coli and Serratia marcescens were employed, and pause RNA synthesis and paused complex release (activation) were quantified relative to synthesis of the terminated leader transcript. It was observed that pausing in the trp leader region was prolonged when translation of the leader transcript was reduced by mutations in the leader region or by addition of the translation inhibitor kasugamycin or chloramphenicol. Experiments with S-30 extracts from a mutant strain that is inefficient in translating the tryptophan codons in the leader transcript indicated that ribosome movement to these codons also releases the paused transcription complex. These findings indicate that the paused trp leader transcription complex resumes transcription when released by ribosome movement over the leader peptide coding region. This release would facilitate the coupling of transcription and translation essential to attenuation control.