The RNA molecule CsrB binds to the global regulatory protein CsrA and antagonizes its activity in Escherichia coli.
The RNA molecule CsrB binds to the global regulatory protein CsrA and antagonizes its activity in Escherichia coli.
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DOI：
10.1074/jbc.272.28.17502
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发表时间：
1997-07-11
影响因子：
4.8
通讯作者：
Romeo, T
中科院分区：
文献类型：
--
作者：
Liu, MY;Gui, GJ;Romeo, T
RNA结合蛋白CsrA（carbon storage regulator）是一种新型的全局性调节因子，能促进特定mRNA的降解。将含有金属结合亲和标签（CsrA-H6）的重组CsrA蛋白纯化至均一，并通过N-末端测序、基质辅助激光解吸/电离飞行时间质谱和其他研究进行鉴定。这种蛋白质完全包含在一个球状复合物的约18 CsrA-H6亚基和一个单一的类似于350个核苷酸的RNA，CsrB。cDNA克隆和核苷酸序列分析表明，csrB基因位于大肠杆菌K-12基因组64分钟区域syd的下游，不含开放阅读框。纯化的CsrA-CsrB核糖核蛋白复合物在体外调节glg（糖原生物合成）基因表达中具有活性，CsrA蛋白的无RNA形式也是如此。csrB的过表达增强了大肠杆菌中糖原的积累。coti，一种被CsrA抑制的固定相过程。因此，CsrB RNA是Csr系统的第二组分，其结合CsrA并拮抗其对基因表达的作用。提出了一个Csr调控相互作用的模型，这也解释了以前在胡萝卜软腐欧文氏菌同源系统上的观察结果。一个高度重复的核苷酸序列位于预测的茎环和其他单链区域的CsrB，CAGGA（U/A/C）G，是一个合理的CsrA结合元件。
The RNA-binding protein CsrA (carbon storage regulator) is a new kind of global regulator, which facilitates specific mRNA decay. A recombinant CsrA protein containing a metal-binding affinity tag (CsrA-H6) was purified to homogeneity and authenticated by N-terminal sequencing, matrix-assisted laser desorption/ionization time of flight mass spectrometry, and other studies. This protein was entirely contained within a globular complex of approximately 18 CsrA-H6 subunits and a single similar to 350-nucleotide RNA, CsrB. cDNA cloning and nucleotide sequencing revealed that the csrB gene is located downstream from syd in the 64-min region of the Escherichia coli K-12 genome and contains no open reading frames. The purified CsrA-CsrB ribonucleoprotein complex was active in regulating glg (glycogen biosynthesis) gene expression in vitro, as was the RNA-free form of the CsrA protein. Overexpression of csrB enhanced glycogen accumulation in E. coti, a stationary phase process that is repressed by CsrA. Thus, CsrB RNA is a second component of the Csr system, which binds to CsrA and antagonizes its effects on gene expression. A model for regulatory inter actions in Csr is presented, which also explains previous observations on the homologous system in Erwinia carotovora. A highly repeated nucleotide sequence located within predicted stem-loops and other single-stranded regions of CsrB, CAGGA(U/A/C)G, is a plausible CsrA-binding element.