NarL, a Novel Repressor for CYP108j1 Expression during PAHs Degradation in Rhodococcus sp. P14
NarL, a Novel Repressor for CYP108j1 Expression during PAHs Degradation in Rhodococcus sp. P14
复制标题
NarL，红球菌 PAH 降解过程中 CYP108j1 表达的新型阻遏蛋白。
DOI：
10.3390/ijms21030983
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发表时间：
2020-02-01
影响因子：
5.6
通讯作者：
Hu, Zhong
中科院分区：
文献类型：
--
作者：
Kan, Jie;Peng, Tao;Hu, Zhong
红球菌属P14是从原油污染的沉积物中分离出来的，广泛的多环芳烃(PAHs)可以作为唯一的碳和能源来源。发现了一个关键的细胞色素P450基因，命名为cyp108j1，与多环芳烃的降解有关，能够羟化多种多环芳烃。然而，cyp108j1表达的调控机制仍不清楚。在本研究中，我们发现cyp108j1的表达受到位于cyp108j1上游的LuxR(酰基高丝氨酸内酯介导的群体感应中的螺旋-转弯-螺旋转录因子)家族调控因子NarL(硝酸盐依赖的双组分调节因子)的负调控。进一步分析表明，NarL可以直接与cyp108j1的启动子区域结合。突变实验表明，NarL与cyp108j1启动子的结合位点为回文序列GAAAGTTG-CAACTTTC。综上所述，这一发现表明NarL是一种新的多环芳烃降解过程中cyp108j1表达的抑制因子。
Rhodococcus sp. P14 was isolated from crude-oil-contaminated sediments, and a wide range of polycyclic aromatic hydrocarbons (PAHs) could be used as the sole source of carbon and energy. A key CYP450 gene, designated as cyp108j1 and involved in the degradation of PAHs, was identified and was able to hydroxylate various PAHs. However, the regulatory mechanism of the expression of cyp108j1 remains unknown. In this study, we found that the expression of cyp108j1 is negatively regulated by a LuxR (helix-turn-helix transcription factors in acyl-homoserine lactones-mediated quorum sensing) family regulator, NarL (nitrate-dependent two-component regulatory factor), which is located upstream of cyp108j1. Further analysis revealed that NarL can directly bind to the promoter region of cyp108j1. Mutational experiments demonstrated that the binding site between NarL and the cyp108j1 promoter was the palindromic sequence GAAAGTTG-CAACTTTC. Together, the finding reveal that NarL is a novel repressor for the expression of cyp108j1 during PAHs degradation.