ROLE OF THE AGA/AGG CODONS, THE RAREST CODONS IN GLOBAL GENE-EXPRESSION IN ESCHERICHIA-COLI
ROLE OF THE AGA/AGG CODONS, THE RAREST CODONS IN GLOBAL GENE-EXPRESSION IN ESCHERICHIA-COLI
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DOI：
10.1101/gad.8.21.2641
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发表时间：
1994-11-01
影响因子：
10.5
通讯作者：
INOUYE, M
中科院分区：
文献类型：
--
作者：
CHEN, GFT;INOUYE, M
精氨酸的阿加和AGG密码子是大肠杆菌中使用最少的密码子。以前的研究表明，这些密码子在E. coli基因。在前25个密码子中具有单个阿加/AGG密码子的100多个基因被鉴定为与各种必需的细胞功能相关。lacZ基因，含有5 AGG密码子后，从起始密码子的第10个密码子，构建作为一个模型系统。β-半乳糖苷酶的产生在稳定期几乎完全被抑制，而不含AGG密码子的对照β-半乳糖苷酶的产生则没有。通过共表达tRNA的argU基因（UCU/CCU）（Arg）或通过将5个AGG密码子移动远离起始密码子>50个密码子，基本上抑制了5个AGG密码子的抑制作用。此外，通过二维凝胶电泳解析的蛋白质的数量的生产显着增强，在稳定期的细胞中携带含有argU的质粒。其中至少一个被鉴定为hns产物，其由在第19位具有阿加密码子的ORF编码。在这些结果的基础上，提出了具有非常接近起始密码子的单个阿加/AGG密码子的一组用于各种细胞功能的必需基因的表达受最低丰度tRA（UCU/CCU）（Arg）的可用性的全局调节。提出了一个模型，为这一规定。
AGA and AGG codons for arginine are the least used codons in Escherichia coli. Previous findings have shown that these codons are used preferentially within the first 25 codons in E. coli genes. More than 100 genes having a single AGA/AGG codon within the first 25 codons were identified to be associated with various essential cellular functions. The lacZ gene, containing 5 AGG codons after the tenth codon from the initiation codon, was constructed as a model system. The production of beta-galactosidase was inhibited almost completely during the stationary phase, whereas the production of the control beta-galactosidase without AGG codons was not. The inhibitory effect by the 5 AGG codons was substantially suppressed either by coexpressing the argU gene for tRNA(UCU/CCU)(Arg) or by moving the 5 AGG codons by >50 codons away from the initiation codon. In addition, the production of a number of proteins resolved by two dimensional gel electrophoresis was enhanced significantly during the stationary phase in the cells harboring a plasmid containing argU. At least one of them was identified as the hns product encoded by an ORF having an AGA codon at the nineteenth position. On the basis of these results, it is proposed that the expression of a group of essential genes for various cellular functions that have a single AGA/AGG codon very close to the initiation codon are globally regulated by the availability of the least abundant tRA(UCU/CCU)(Arg). A model for this regulation is proposed.