Molecular cloning of an essential subunit of RNA polymerase II elongation factor SIII.
Molecular cloning of an essential subunit of RNA polymerase II elongation factor SIII.
复制标题
RNA 聚合酶 II 延伸因子 SIII 的重要亚基的分子克隆。
DOI：
10.1073/pnas.91.12.5237
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发表时间：
1994
影响因子：
11.1
通讯作者：
Conaway,RC
中科院分区：
文献类型：
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作者：
Garrett,KP;Tan,S;Bradsher,JN;Lane,WS;Conaway,JW;Conaway,RC
最近从哺乳动物细胞中纯化出一种称为SIII的转录因子，并显示其调节RNA聚合酶II延伸复合物的活性。SIII是由大约110-、18-和15-kDa多肽组成的异源三聚体，并且能够通过抑制聚合酶在DNA模板上的多个位点处的瞬时暂停来增加RNA聚合酶II的RNA链延伸的总体速率。在这里，我们描述的分子克隆和表征的cDNA编码的功能15 kDa的亚基（p15）的SIII。p15 cDNA编码一个112个氨基酸的多肽，计算分子量为12，473 Da，电泳迁移率与天然p15亚基无区别。当与110-和18-kDa SIII亚基结合时，细菌表达的p15有效地取代了转录活性SIII重建中的天然p15亚基。同源性搜索显示，SIII p15亚基的氨基末端的一半与大肠杆菌转录终止蛋白rho的RNA结合结构域的一部分以及与大肠杆菌的RNA结合结构域的一部分具有显著的序列相似性。coliNusB蛋白，表明SIII可能与真细菌中参与转录延伸控制的蛋白质进化相关。
A transcription factor designated SIII was recently purified from mammalian cells and shown to regulate the activity of the RNA polymerase II elongation complex. SIII is a heterotrimer composed of approximately 110-, 18-, and 15-kDa polypeptides and is capable of increasing the overall rate of RNA chain elongation by RNA polymerase II by suppressing transient pausing of polymerase at multiple sites on the DNA template. Here we describe the molecular cloning and characterization of a cDNA encoding the functional 15-kDa subunit (p15) of SIII. The p15 cDNA encodes a 112-amino-acid polypeptide with a calculated molecular mass of 12,473 Da and an electrophoretic mobility indistinguishable from that of the natural p15 subunit. When combined with the 110- and 18-kDa SIII subunits, bacterially expressed p15 efficiently replaces the natural p15 subunit in reconstitution of transcriptionally active SIII. A homology search revealed that the amino-terminal half of the SIII p15 subunit shares significant sequence similarity with a portion of the RNA-binding domain of Escherichia coli transcription termination protein rho and with the E. coli NusB protein, suggesting that SIII may be evolutionarily related to proteins involved in the control of transcription elongation in eubacteria.
DOI：
--
发表时间：
1994
期刊：
影响因子：
--
作者：
R. Conaway;J. Conaway
通讯作者：
J. Conaway