TetR家族调控链霉菌次级代谢的机制

TetR family proteins in regulation of secondary metabolism in Streptomyces

链霉菌和其他放线菌是活性天然产物的重要来源。随着基因组测序结果的飞速积累,人们发现链霉菌中蕴含丰富的次级代谢途径,远远超过实验室常规条件下检测到的天然产物数量。链霉菌次级代谢途径的表达受到精密而复杂的代谢调控网络的控制。链霉菌中的TetR家族成员数量大、作用机制多样,是调控网络的重要成员。链霉菌TetR家族的成员通过配体结合域结合γ-丁酸内酯(Gamma butyrolactone,GBL)信号分子或其他小分子配体,感受外界环境变化,对下游靶基因进行阻遏或激活,从而对次级代谢进行调控。本文从TetR家族的功能及结合配体的类型对该家族成员进行分类,并总结一些已经被证实在链霉菌次级代谢调控中发挥作用的TFRs(TetR family transcriptional regulators)的作用机制。

Streptomyces and other actinobacteria are important sources for bioactive products.In the light of whole genome sequencing technology, people have gained further information about Streptomyces. There exists a plethora of secondary metabolic pathways in Streptomyces, which exceeds the number of natural products that have been isolated under normal laboratory conditions. The expression of secondary metabolic pathways is regulated by a precise and so- phisticated regulatory network. TetR family in Streptomyces is of great value in the regulatory network due to its huge number and multifunction. TetR family members could sense the en- vironment changes through binding to specific GBL （gamma butyrolactone） molecules or other ligands with the help of the ligand binding domain, and subsequently repress or activate sec- ondary pathways through regulating the expression of downstream target genes. This review will focus on the classification of TetR family proteins in Streptomyces based on their function and ligands they bind, and list the regulatory mechanism of known TFRs （TetR family regula- tors） on secondary metabolism in Streptomyces.