ESCHERICHIA-COLI RIBOSOMES TRANSLATE INVIVO WITH VARIABLE-RATE
ESCHERICHIA-COLI RIBOSOMES TRANSLATE INVIVO WITH VARIABLE-RATE
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DOI：
10.1002/j.1460-2075.1984.tb02227.x
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发表时间：
1984-01-01
期刊：
影响因子：
11.4
通讯作者：
PEDERSEN, S
中科院分区：
文献类型：
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作者：
PEDERSEN, S
通过测量稀有密码子丰富的2个基因lacI和bla的翻译时间，并将结果与稀有密码子很少的fus、tsf、tuf和rpsA的翻译时间进行比较，研究了“稀有"密码子是否以与”常见"密码子相同的速率翻译的问题。首先用高拷贝数质粒pBR 322上存在的上启动子突变lacI 1测量lac阻遏物的合成速率。在这样的菌株中，lacI和bla的平均翻译时间比从4种核糖体蛋白的翻译时间计算的速率慢50%。在F“lac附加体上具有lacIq 1的菌株中，这种差异要小得多，因此富含稀有密码子的基因的缓慢翻译在稀有密码子tRNA消耗增加的菌株中被夸大。这些数据并不排除只有一部分稀有密码子翻译得更慢。还测量了在不同培养基中生长的细胞中的翻译时间，并且翻译链生长速率增加了apprx。从醋酸盐培养基到完全补充的培养基，40%。
The question of whether or not ''rare'' codons are translated with the same rate as ''common'' codons was investigated by measuring the translation time for 2 genes, lacI and bla, rich in rare codons, and comparing the results with the translation times measured on fus, tsf, tuf and rpsA which have very few rare codons. The rate of synthesis of the lac repressor was first measured with the up-promoter mutation lacI1 present on the high copy number plasmid pBR322. In such a strain the average translation times for lacI and bla were 50% slower than the rate calculated from the translation time for the 4 ribosomal proteins. In a strain having lacIq1 on an F''lac episome this difference was much smaller, thus slow translation of genes rich in rare codons in exaggerated in strains with increased drain on the rare codon tRNA. The data do not exclude that only a subset of the rare codons is translated more slowly. Translation times were also measured in cells growing in different media, and the translation chain growth rate increased by .apprx. 40% going from acetate medium to a fully supplemented medium.