THE AGG CODON IS TRANSLATED SLOWLY IN ESCHERICHIA-COLI EVEN AT VERY LOW EXPRESSION LEVELS
THE AGG CODON IS TRANSLATED SLOWLY IN ESCHERICHIA-COLI EVEN AT VERY LOW EXPRESSION LEVELS
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DOI：
10.1093/nar/16.7.3013
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发表时间：
1988-04-11
影响因子：
14.9
通讯作者：
JENSEN, KF
中科院分区：
文献类型：
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作者：
BONEKAMP, F;JENSEN, KF
所提供的数据表明，精氨酸的AGG密码子的翻译显著慢于相同氨基酸的CGU密码子，即使当它们从探针的表达水平非常低时。将两种类型的密码子（三个串联）插入pyrE衰减子前面的人工前导肽基因中的多拷贝质粒上，其中转录终止的频率由转录和翻译之间的偶联程度调节。操纵子的转录依赖于lac-operon诱导剂IPTG的浓度从lac-promoter启动。在所有诱导水平下，发现当前导序列中存在AGG密码子时，通过pyrE衰减子的转录频率比存在CGT密码子时低约9倍。这表明AGG密码子在pyrE衰减子区域中将翻译与转录解耦，即使当该密码子的浓度相对于未干扰的野生型菌株中的浓度没有显著增加时。因此，结果表明AGG密码子在大肠杆菌中总是缓慢翻译。
Data are presented which indicate that AGG codons for arginine are translated significantly more slowly than the CGU codons for the same amino acid even when their expression level from the probe is very low. The two types of codons were inserted (three in tandem) on a multicopy plasmid in an artificial leader peptide gene in front of the pyrE attenuator where the frequency of transcription termination is regulated by the degree of coupling between transcription and translation. Transcription of the operon is initiated from the lac-promoter dependent on the concentration of the lac-operon inducer IPTG. At all induction levels it was found that the frequency of transcription past the pyrE attenuator was approximately nine time lower when the AGG codons were present in the leader than with CGT codons present. This shows that AGG codons decouple translation from transcription in the pyrE attenuator region even when the concentration of this codon is not increased significantly relative to that in the unperturbed wild type strain. Thus the results indicate that AGG codons are always slowly translated in Escherichia coli.