Ribonuclease E organizes the protein interactions in the Escherichia coli RNA degradosome
Ribonuclease E organizes the protein interactions in the Escherichia coli RNA degradosome
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DOI：
10.1101/gad.12.17.2770
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发表时间：
1998-09-01
影响因子：
10.5
通讯作者：
Carpousis, AJ
中科院分区：
文献类型：
--
作者：
Vanzo, NF;Li, YS;Carpousis, AJ
大肠杆菌RNA降解体是最近发现的参与RNA加工和降解的多蛋白质机器家族的原型。RNA降解体的各种蛋白质组分之间的相互作用进行了研究，通过远Western印迹，酵母双杂交试验，和coimmunopurification实验。我们的研究结果表明，核糖核酸酶E（RNase E）的羧基末端的一半（CTH）包含的其他三个主要降解体成分，DEAD盒RNA解旋酶RhlB，烯醇化酶，和多核苷酸磷酸化酶（PNDG）的结合位点。RNase E的CTH充当复合物的支架，其他降解体组分在其上组装。在RNase E的氨基末端和中心区域检测到寡聚化区域。此外，衍生自RNA酶E的高电荷区的多肽，含有Rh1B结合位点，刺激Rh1B活性至少15倍，饱和于每个Rh1B分子一个多肽。提出了一种调节RhlB RNA解旋酶活性的模型。现在出现的RNase E的描述是一种非常复杂的多结构域蛋白质，含有氨基末端催化结构域，中央RNA结合结构域和RNA降解体其他主要成分的羧基末端结合位点。
The Escherichia coli RNA, degradosome is the prototype of a recently discovered family of multiprotein machines involved in the processing and degradation of RNA. The interactions between the various protein components of the RNA degradosome were investigated by Far Western blotting, the yeast two-hybrid assay, and coimmunopurification experiments. Our results demonstrate that the carboxy-terminal half (CTH) of ribonuclease E (RNase E) contains the binding sites for the three other major degradosomal components, the DEAD-box RNA helicase RhlB, enolase, and polynucleotide phosphorylase (PNPase). The CTH of RNase E acts as the scaffold of the complex upon which the other degradosomal components are assembled. Regions for oligomerization were detected in the amino-terminal and central regions of RNase E. Furthermore, polypeptides derived from the highly charged region of RNase E, containing the RhlB binding site, stimulate RhlB activity at least 15-fold, saturating at one polypeptide per RhlB molecule. A model for the regulation of the RhlB RNA helicase activity is presented. The description of RNase E now emerging is that of a remarkably complex multidomain protein containing an amino-terminal catalytic domain, a central RNA-binding domain, and carboxy-terminal binding sites for the other major components of the RNA degradosome.