Reprint of: Inhibition of Escherichia coli RNAp by T7 Gp2 protein: Role of Negatively Charged Strip of Amino Acid Residues in Gp2
Reprint of: Inhibition of Escherichia coli RNAp by T7 Gp2 protein: Role of Negatively Charged Strip of Amino Acid Residues in Gp2
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DOI：
10.1016/j.jmb.2011.07.064
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发表时间：
2011-10-07
影响因子：
5.6
通讯作者：
Wigneshweraraj, Siva R.
中科院分区：
文献类型：
--
作者：
Sheppard, Carol;Camara, Beatriz;Wigneshweraraj, Siva R.
Gp2是由T7噬菌体编码的7kDa蛋白，是大肠杆菌RNA聚合酶（RNAp）的有效抑制剂，RNA聚合酶负责所有细菌基因和早期病毒基因的转录。Gp2结构中的一个突出特征是位于分子沿着一侧的七个带负电荷的氨基酸残基的连续条带（带负电荷的条带或NCS）。NCS在Gp2功能中的作用尚不清楚。在这里，在NCS中的氨基酸取代的Gp2的改变形式的体内和体外特性进行了描述。虽然NCS中的突变不损害Gp2的折叠或结合RNAp β '亚基的能力，但NCS的破坏显著减弱了Gp2在体内的功能及其在体外抑制RNAp的能力。Gp2对RNAp的有效抑制还涉及位于β ′中主要Gp2结合位点附近的RNAp启动子特异性亚基σ（70）的氨基末端区域1结构域。结果进行了讨论的背景下，假设的分子机制的RNA抑制Gp2。(C)爱思唯尔有限公司出版
Gp2, a 7 kDa protein encoded by T7 bacteriophage, is a potent inhibitor of Escherichia coli RNA polymerase (RNAp), the enzyme responsible for transcription of all bacterial genes and early viral genes. A prominent feature in the structure of Gp2 is a contiguous strip of seven negatively charged amino acid residues (negatively charged strip or NCS), located along one side of the molecule. The role of the NCS in Gp2 function is not known. Here, the in vivo and in vitro properties of altered forms of Gp2 with amino acid substitutions in the NCS are described. While mutations in the NCS do not compromise the folding or the ability of Gp2 to bind to the RNAp beta' subunit, disruption of the NCS significantly attenuates Gp2 function in vivo and its ability to inhibit RNAp in vitro. Efficient inhibition of the RNAp by Gp2 also involves the amino terminal region 1 domain of the RNAp promoter specificity subunit sigma(70) located in the vicinity of the primary Gp2 binding site in beta'. The results are discussed in the context of hypothetical molecular mechanisms of RNAp inhibition by Gp2. (C) 2011 Published by Elsevier Ltd.