Structural basis of transcription activation by Rob, a pleiotropic AraC/XylS family regulator.
Structural basis of transcription activation by Rob, a pleiotropic AraC/XylS family regulator.
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DOI：
10.1093/nar/gkac433
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发表时间：
2022-06-10
影响因子：
14.9
通讯作者：
Lin, Wei
中科院分区：
文献类型：
--
作者：
Shi, Jing;Wang, Fulin;Li, Fangfang;Wang, Lu;Xiong, Ying;Wen, Aijia;Jin, Yuanling;Jin, Sha;Gao, Fei;Feng, Zhenzhen;Li, Jiacong;Zhang, Yu;Shang, Zhuo;Wang, Shuang;Feng, Yu;Lin, Wei
Rob作为大的AraC/XylS家族转录激活因子的范例，调节参与多药耐药和应激反应的基因的不同子集。然而，它如何使细菌RNA聚合酶和启动子DNA对环境刺激做出精细反应的潜在机制仍然难以捉摸。在这里，我们提出了两个冷冻电镜结构的罗布依赖的转录激活复合物（Rob-TAC），包括大肠杆菌RNA聚合酶（RNAP），罗布调控的启动子和罗布在替代构象。结构表明，单个Rob通过与RNAP αCTD和σ 70 R4相互作用来接合RNAP，揭示了它们通常重要的调节作用。值得注意的是，通过阻断σ 70 R4与-35元件的结合，Rob通过其共有HTH基序特异性结合保守的Rob结合盒，并借助于辅助酸性环保留DNA弯曲。更引人注目的是，我们的配体对接和生化分析表明，大罗布C-末端结构域（罗布CTD）与全球Gyrl样结构域在效应器结合和变构调节中具有很大的结构相似性，并协调促进形成主管Rob-TAC。总之，我们的结构和生化数据突出了Rob-dependent转录激活的详细分子机制，并为了解其他AraC/XylS-家族转录因子的生理作用提供了有利的证据。
Rob, which serves as a paradigm of the large AraC/XylS family transcription activators, regulates diverse subsets of genes involved in multidrug resistance and stress response. However, the underlying mechanism of how it engages bacterial RNA polymerase and promoter DNA to finely respond to environmental stimuli is still elusive. Here, we present two cryo-EM structures of Rob-dependent transcription activation complex (Rob-TAC) comprising of Escherichia coli RNA polymerase (RNAP), Rob-regulated promoter and Rob in alternative conformations. The structures show that a single Rob engages RNAP by interacting with RNAP αCTD and σ70R4, revealing their generally important regulatory roles. Notably, by occluding σ70R4 from binding to -35 element, Rob specifically binds to the conserved Rob binding box through its consensus HTH motifs, and retains DNA bending by aid of the accessory acidic loop. More strikingly, our ligand docking and biochemical analysis demonstrate that the large Rob C-terminal domain (Rob CTD) shares great structural similarity with the global Gyrl-like domains in effector binding and allosteric regulation, and coordinately promotes formation of competent Rob-TAC. Altogether, our structural and biochemical data highlight the detailed molecular mechanism of Rob-dependent transcription activation, and provide favorable evidences for understanding the physiological roles of the other AraC/XylS-family transcription factors.
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影响因子：
64.5
作者：
Feklistov A;Darst SA
通讯作者：
Darst SA
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.6
作者：
Dangi, B;Gronenborn, AM;Martin, RG
通讯作者：
Martin, RG
影响因子：
16
作者：
Chen, James;Chiu, Courtney;Darst, Seth A.
通讯作者：
Darst, Seth A.
DOI：
10.1261/rna.056226.116
发表时间：
2016-12
期刊：
RNA (New York, N.Y.)
影响因子：
--
作者：
Jeng SC;Chan HH;Booy EP;McKenna SA;Unrau PJ
通讯作者：
Unrau PJ