Characterization of novel regulatory mechanism for the catabolic genes of aromatic compound degradation

为了明确联苯（BP）分解代谢途径基因转录的调控机制，对一个IclR型转录调控基因tsdR进行了鉴定，该基因的转录受BP分解代谢双组分调控系统的调控。对在BP存在或不存在下生长的tsdR缺失突变体的转录组分析的结果表明，TsdR调节的基因参与BP催化。使用纯化的TsdR和含有tsdB和tsdT的2，6-二羟基苯甲酸酯（26 DHB）分解代谢基因的启动子区的电泳迁移率变动分析显示，TsdR结合到tsd启动子区，并且该结合被添加26 DHB抑制。这些结果表明，TsdR作为一个阻遏物的tsd基因的转录和26 DHB与TsdR相互作用的效应分子。

In order to identify the regulatory mechanism for the transcription of biphenyl (BP) catabolic pathway genes in Rhodococcus jostii RHA1, an IclR-type transcriptional regulator gene, tsdR, whose transcription is controlled by two-component regulatory system of BP catabolism, was characterized. The results of the transcriptome analysis of tsdR deletion mutant grown with or without BP suggesting that the TsdR-regulated genes are involved in the BP catabolism. Electrophoretic mobility shift assays using purified TsdR and the promoter regions of 2,6-dihydroxybenzaote (26DHB) catabolic genes containing tsdB and tsdT revealed that the TsdR binds to the tsd promoter regions and the bindings are inhibited by the addition of 26DHB. These results indicate that TsdR acts as a repressor for the transcription of tsd genes and 26DHB interacts with TsdR as an effector molecule.