A novel role of ImmE7 in the autoregulatory expression of the ColE7 operon and identification of possible RNase active sites in the crystal structure of dimeric ImmE7
A novel role of ImmE7 in the autoregulatory expression of the ColE7 operon and identification of possible RNase active sites in the crystal structure of dimeric ImmE7
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ImmE7 在 ColE7 操纵子的自动调节表达中的新作用以及二聚体 ImmE7 晶体结构中可能的 RNase 活性位点的鉴定
DOI：
10.1093/emboj/16.6.1444
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Hanna S. Yuan
中科院分区：
文献类型：
--
作者：
S. Hsieh;T. Ko;Ming‐Yu Tseng;W. Ku;K. Chak;Hanna S. Yuan
已在体内鉴定出多顺反子大肠杆菌素 E7 操纵子 (ColE7) 的 mRNA 位点特异性切割，该切割发生在位于免疫基因 (ceiE7) 的 Asp52 密码子 (GAT) 的 G 和 A 核苷酸之间。在体外，这种特异性切割仅在存在 ceiE7 基因产物 (ImmE7) 的情况下发生。二聚体 ImmE7 的晶体结构已通过 X 射线晶体学分析以 1.8 Å 分辨率确定。我们发现位于二聚体 ImmE7 界面的几个残基与一些 RNase 的活性位点具有惊人的相似性。这些结果表明二聚体ImmE7可能具有一种新的RNase活性，可以在特定位点切割其自身的mRNA，从而自动调节下游celE7基因的翻译表达以及上游ceaE7 mRNA的降解。
Site‐specific cleavage of mRNA has been identified in vivo for the polycistronic colicin E7 operon (ColE7), which occurs between G and A nucleotides located at the Asp52 codon (GAT) of the immunity gene (ceiE7). In vitro, this specific cleavage occurs only in the presence of the ceiE7 gene product (ImmE7). The crystal structure of dimeric ImmE7 has been determined at 1.8 Å resolution by X‐ray crystallographic analysis. We found that several residues located at the interface of dimeric ImmE7 bear surprising resemblance to the active sites of some RNases. These results suggest that dimeric ImmE7 may possess a novel RNase activity that cleaves its own mRNA at a specific site and thus autoregulates translational expression of the downstream celE7 gene as well as degradation of the upstream ceaE7 mRNA.
DOI：
10.1073/pnas.80.3.653
发表时间：
1983-02
影响因子：
11.1
作者：
A. von Gabain;J. Belasco;J. Schottel;A. C. Chang;S. Cohen
通讯作者：
A. von Gabain;J. Belasco;J. Schottel;A. C. Chang;S. Cohen