Interaction Surface of the Transcription Terminator Rho Required to Form a Complex with the C-Terminal Domain of the Antiterminator NusG
Interaction Surface of the Transcription Terminator Rho Required to Form a Complex with the C-Terminal Domain of the Antiterminator NusG
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DOI：
10.1016/j.jmb.2010.10.044
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发表时间：
2011-01-07
影响因子：
5.6
通讯作者：
Sen, Ranjan
中科院分区：
文献类型：
--
作者：
Chalissery, Jisha;Muteeb, Ghazala;Sen, Ranjan
细菌中 Rho 依赖性转录终止需要终止子 Rho 和抗终止子 NusG 之间的相互作用。 Rho-NusG 复合物的相互作用表面未知。在这里，我们提供了直接证据，证明 NusG (NusG-CTD) C 端结构域的 β 折叠束具有 Rho 的结合决定簇，证明了之前描述的假设 [Mooney, R. A.、Schweimer, K.、Rosch, P.、Gottesman, M. 和 Landick, R., (2009)。大肠杆菌 NusG 的两个结构独立的结构域通过与 RNA 聚合酶和调节因子的独特相互作用产生调节可塑性。 J.莫尔。生物学，391, 341-358.]。可以使用 Rho 表面暴露的氨基酸 217 和 224（属于其 P 环 ATP 酶结构域）从 NusG-CTD 构建二硫桥。对 Rho 该区域的突变分析表明，位于 Rho 这些氨基酸后面的疏水口袋是 NusG-CTD 的对接位点。 Rho-NusG 复合物中 Rho 的该区域与 NusG-CTD 的接近性也通过 Rho 的残基 K224 和 NusG-CTD 的残基 A168 之间的有效荧光共振能量转移得到证实。 Rho-NusG 相互作用表面的识别不仅有助于理解 NusG 在终止过程中的作用，而且有助于解释 NusG-CTD 参与将 Rho 和核糖体招募到同一转录机制中的分子基础。 (c) 2010 Elsevier Ltd. 保留所有权利。
Rho-dependent transcription termination in bacteria requires an interaction between the terminator Rho and the antiterminator NusG. The interaction surface of the Rho-NusG complex is unknown. Here we provide direct evidence that the beta-sheet bundle of the C-terminal domain of NusG (NusG-CTD) has the binding determinants for Rho, proving the hypothesis described earlier [Mooney, R. A., Schweimer, K., Rosch, P., Gottesman, M., & Landick, R., (2009). Two structurally independent domains of E. coli NusG create regulatory plasticity via distinct interactions with RNA polymerase and regulators. J. Mol. Biol., 391, 341-358.]. Disulfide bridges can be engineered from NusG-CTD with the surface-exposed amino acids 217 and 224 of Rho, which belong to its P-loop ATPase domain. Mutational analyses of this region of Rho revealed that a hydrophobic pocket, located behind these amino acids of Rho, is the docking site for NusG-CTD. The proximity of this region of Rho to NusG-CTD in the Rho-NusG complex was also confirmed by an efficient fluorescence resonance energy transfer between residue K224 of Rho and residue A168 of NusG-CTD. The identification of the Rho-NusG interaction surface will be useful not only in understanding the role of NusG in the termination process but also in explaining the molecular basis of the involvement of NusG-CTD in recruiting Rho and the ribosome to the same transcription machinery. (c) 2010 Elsevier Ltd. All rights reserved.