转录因子SoxR的结构、调控机制及生理功能

Structure, mechanism and roles of the transcription factor SoxR in bacteria－A review

摘要:

摘要：转录因子SoxR是典型的汞抗性操纵子调节因子家族的成员，广泛存在于变形菌门、放线菌门、酸杆菌门等微生物类群中。SoxR感受胞内氧化还原电势，通过铁硫簇失去一个电子，而激活目标基因的表达。SoxR在大肠杆菌中能应答过氧化物，负责抗氧化胁迫的全局性调控；在铜绿假单胞菌中受群体感应终端信号分子绿脓菌素的激活，参与群体对环境变化的协同应答过程。本文综述了SoxR的结构、作用机制和生理功能。近年来关于SoxR的研究虽然已取得许多令人瞩目的成果，但SoxR激活的分子机制仍有待确立和验证，同时也亟待在更多微生物类群中开展相关研究。对这些问题的深入研究，不仅可以更全面地认识SoxR，而且可以对微生物体的整个代谢调控网络有更加深入地了解，并有可能获得里程碑式的重大发现。

Abstract:

Abstract: The transcription factor SoxR is a typical member of the family of mercury resistance operon regulator (MerR), extensively distributed across several bacterial phyla, such as Proteobacteria, Actinobacteria and Acidobacteria. SoxR, which is initially regarded as a cellular redox sensor, is activated by reversible one-electron oxidation of the [2Fe-2S] cluster and then enhances the expression of its target genes. SoxR responds to the oxidative stress mediated by superoxides in Escherichia coli in a global manner, whereas it coordinates the bacterial community growth adapted to the environment in Pseudomonas aeruginosa by sensing pyocyanin, which is a terminal signaling factor in the quorum sensing network. In this review, we focused on the structure, mechanism and roles of the transcription factor SoxR. Although compelling achievements have been made in recent years, some aspects still remain to be unraveled. A widely accepted mechanism of activation of SoxR has not yet been established or validated. And there is much and urgent call for intensive studies from more taxonomic groups rather than E. coli and P. aeruginosa. With more and more work done on these aspects, one can not only understand SoxR more comprehensively, but also gain deeper insights into the bacterial complex regulation networks, and even achieve milestones in this field.