IDENTIFICATION OF RIBOSOMAL-PROTEIN S7 AS A REPRESSOR OF TRANSLATION WITHIN THE STR OPERON OF ESCHERICHIA-COLI
IDENTIFICATION OF RIBOSOMAL-PROTEIN S7 AS A REPRESSOR OF TRANSLATION WITHIN THE STR OPERON OF ESCHERICHIA-COLI
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DOI：
10.1016/0092-8674(81)90331-7
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发表时间：
1981-01-01
期刊：
影响因子：
64.5
通讯作者：
NOMURA, M
中科院分区：
文献类型：
--
作者：
DEAN, D;YATES, JL;NOMURA, M
用DNA指导的体外蛋白质合成系统证明r（核糖体）蛋白S7具有抑制str操纵子的第二和第三基因产物（S7和EF-G，延伸因子G）的mRNA翻译的能力，但不抑制第一基因产物（S12）。操纵子中最后一个基因产物（EF-Tu）的mRNA翻译也可能不受S7抑制。通过使用含有S7基因的各种模板DNA在体外检查S7的阻遏活性，将S7阻遏作用的靶位点定位在多顺反子str mRNA上。靶位点不包括S12的mRNA的启动子近端部分。为了测试S7在体内的调节特性，将S7基因插入到含有ara调节元件的质粒载体中，使得S7合成置于ara控制下。由阿拉伯糖启动子引起的转录刺激引起的S7合成的特异性增加降低了EF-G的合成速率，但对S12或EF-Tu合成没有影响。
A DNA-directed in vitro protein-synthesizing system was used to demonstrate that r (ribosomal) protein S7 has the capacity to inhibit the translation of mRNA for the 2nd and 3rd gene products of the str operon (S7 and EF-G, elongation factor G) but not for the 1st gene product (S12). Translation of mRNA of the last gene product in the operon (EF-Tu) is also probably not inhibited by S7. The target site for S7 repressor action was localized on the polycistronic str mRNA by examining the repressor activity of S7 in vitro using various template DNA that contain the S7 gene. The target site did not include a promoter-proximal portion of the mRNA for S12. To test for regulatory properties of S7 in vivo, the S7 gene was inserted into a plasmid vector containing the ara regulatory elements such that S7 synthesis was placed under ara control. A specific increase in S7 synthesis caused by stimulation in transcription originating from the arabinose promoter decreased the synthetic rate for EF-G but had no effect on S12 or EF-Tu synthesis.