Characterization and modification of molecular mechanism for transcriptional regulation of the degradation enzyme system of an environmental pollutant

Jostii红球菌RHA 1是一种对环境污染物多氯联苯（PCBs）具有很强降解能力的细菌。其降解酶的诱导需要诱导底物，并由一对双组分转录调节因子BphS 1 T1和BphS 2 T2进行。研究了BphS 1 T1和BphS 2 T2的转录调控机制，以开发其PCB降解酶由PCB本身诱导的菌株。在诱导底物的存在下，BphT（BphT 1/T2）的磷酸化被指示。降解酶基因操纵子启动子之间共享一个新的24-bp的共有序列，并且具有BphST转录诱导所必需的和足够的功能，这表明24-bp的序列为包括BphT的转录复合物的结合位点服务。

Rhodococcus jostii RHA1 is a strong degrader of the environmental pollutant, polychlorinated biphenyls (PCBs). Induction of its degradation enzymes requires an inducing substrate and is conducted by a couple of two-component transcriptional regulators, BphS1T1 and BphS2T2. Mechanism of transcriptional regulation of BphS1T1 and BphS2T2 were examined to develop a strain whose PCB-degradation enzymes are induced by PCBs themselves. Phosphorylation of BphT (BphT1/T2) in the presence of the inducing substrate was indicated. A novel 24-bp consensus sequence was shared among the degradation enzyme gene operon promoters and had necessary and sufficient function for transcriptional induction by BphST, suggesting that the 24-bp sequence serves the binding site for the transcriptional complex including BphT.