Expression of the nitroarene dioxygenase genes in Comamonas sp strain JS765 and Acidovorax sp strain JS42 is induced by multiple aromatic compounds
Expression of the nitroarene dioxygenase genes in Comamonas sp strain JS765 and Acidovorax sp strain JS42 is induced by multiple aromatic compounds
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DOI：
10.1128/jb.185.13.3895-3904.2003
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发表时间：
2003-07-01
影响因子：
3.2
通讯作者：
Gibson, DT
中科院分区：
文献类型：
--
作者：
Lessner, DJ;Parales, RE;Gibson, DT
本工作报告了在Comamonas sp.菌株JS 765中硝基苯双加氧酶（NBDO）和在Acidovorax sp.菌株JS 42中2-硝基甲苯双加氧酶（2NTDO）的表达的遗传分析。菌株JS 765和JS 42分别具有相同的LysR型调节蛋白NbzR和NtdR。NbzR/NtdR与恶臭假单胞菌G7中萘降解基因的正水杨酸响应性转录激活因子NahR同源。每个菌株中编码NBDO和2NTDO的基因共转录，并且转录在每个操纵子的相同启动子区内的相同位点开始。lacZ报告基因融合的结果表明，NBDO和2NTDO的表达是由多种芳香族化合物，包括一系列的硝基芳香族化合物（硝基苯，2-，3-，和4-硝基甲苯，2，4-和2，6-二硝基甲苯，和氨基二硝基甲苯），以及水杨酸盐和邻氨基苯甲酸盐诱导。硝基芳族化合物似乎是实际的效应分子。用菌株JS 42进行的P-半乳糖苷酶和2NTDO活性的分析表明，NtdR是所有诱导化合物的诱导、2NTDO的高基础水平表达和JS 42 ntdR无效突变体的互补所需的。与密切相关的调节剂NagR（从罗尔斯通氏菌菌株U2）和NahR的互补恢复仅诱导的原型诱导剂，水杨酸盐或水杨酸盐和邻氨基苯甲酸盐，分别，并没有恢复高基础水平的表达2NTDO。JS 42中2NTDO基因调控的机制，以及推测JS 765中NBDO基因调控的机制，似乎与恶臭假单胞菌G7中NahR调控基因的机制相似。然而，NbzR和NtdR似乎在JS 42和JS 765中进化出了更广泛的特异性，允许识别硝基芳族化合物，同时保留对水杨酸盐和邻氨基苯甲酸盐的响应能力。NtdR也是硝基芳烃响应性LysR型转录激活因子的第一个例子。
This work reports a genetic analysis of the expression of nitrobenzene dioxygenase (NBDO) in Comamonas sp. strain JS765 and 2-nitrotoluene dioxygenase (2NTDO) in Acidovorax sp. strain JS42. Strains JS765 and JS42 possess identical LysR-type regulatory proteins, NbzR and NtdR, respectively. NbzR/NtdR is homologous to NahR, the positive salicylate-responsive transcriptional activator of the naphthalene degradation genes in Pseudomonas putida G7. The genes encoding NBDO and 2NTDO in each strain are cotranscribed, and transcription starts at the same site within identical promoter regions for each operon. Results from a lacZ reporter gene fusion demonstrated that expression of NBDO and 2NTDO is induced by multiple aromatic compounds, including an array of nitroaromatic compounds (nitrobenzene, 2-, 3-, and 4-nitrotoluene, 2,4- and 2,6-dinitrotoluene, and aminodinitrotoluenes), as well as salicylate and anthranilate. The nitroaromatic compounds appear to be the actual effector molecules. Analysis of P-galactosidase and 2NTDO activities with strain JS42 demonstrated that NtdR was required for induction by all of the inducing compounds, high basal-level expression of 2NTDO, and complementation of a JS42 ntdR null mutant. Complementation with the closely related regulators NagR (from Ralstonia sp. strain U2) and NahR restored only induction by the archetype inducers, salicylate or salicylate and anthranilate, respectively, and did not restore the high basal level of expression of 2NTDO. The mechanism of 2NTDO gene regulation in JS42, and presumably that of NBDO gene regulation in JS765, appear similar to that of NahR-regulated genes in Pseudomonas putida G7. However, NbzR and NtdR appear to have evolved a broader specificity in JS42 and JS765, allowing for recognition of nitroaromatic compounds while retaining the ability to respond to salicylate and anthranilate. NtdR is also the first example of a nitroarene-responsive LysR-type transcriptional activator.