近日，国际著名杂志The Journal of Biological Chemistry刊登了韩国高丽大学研究人员的最新研究成果“Atp-dependent RecG helicase is required for the transcriptional regulator OxyR function in Pseudomonas species”，文章中，研究者揭示了在假单胞菌中，ATP依赖的RecG解旋酶对于转录调节子OxyR的重要作用。
oxyR基因和recG解旋酶基因在许多细菌广泛存在，这些细菌包括致病性的铜绿假单胞菌和恶臭假单胞菌。对恶臭假单胞菌的转录组学分析结果显示，许多OxyR控制的基因同时也受ATP依赖的RecG解旋酶的调节，而且RecG也可以调节许多基因的表达。
在大肠杆菌和肠炎沙门氏菌中，OxyR可以调节很多涉及抵御过氧化氢诱导的氧化压力的相关基因的功能，OxyR对于氧化还原物质敏感而且可以在过氧化氢存在的情况下产生胞内的二硫化物结合物。
转录组学分析结果显示，恶臭假单胞菌的氧化压力效应相关研究并没有人报道，而且在该菌种OxyR并没有定论，具有DNA修复功能的RecG在氧化压力的条件下已经进行了相关的研究，但是RecG和OxyR之间的联系却并不清楚。
在这项研究中，研究者通过研究表明，RecG可以直接结合到OxyR结合位点的回文序列，而且RecG对于OxyR介导的抵御氧化压力的效应激活必不可少。RecG也可以影响许多促进产生回文序列特征的基因的表达。研究者Woojun Park最后表示，RecG同时需要镁离子和ATP来维持其功能。本研究中，研究者发现了RecG的一个新的机制，为科学家研究细菌的转录调节机制提供了新的见解。（生物谷Bioon.com）
编译者：T.Shen
doi:10.1074/jbc.M112.356964
PMC:
PMID:
ATP-dependent RecG helicase is required for the transcriptional regulator OxyR function in Pseudomonas species
Jinki Yeom, Yunho Lee and Woojun Park*
The oxyR gene appears to reside in an operon with the recG helicase gene in many bacteria, including pathogenic Pseudomonas aeruginosa and P. putida. Analysis of P. putida transcriptomes shows that many OxyR-controlled genes are regulated by the ATP-dependent RecG helicase, and that RecG alone modulates the expression of many genes. We found that purified RecG binds to the promoters of many OxyR-controlled genes and that expression of these genes was not induced under conditions of oxidative stress in recG mutants of P. aeruginosa, P. putida, and Escherichia coli. In vitro data revealed that promoters containing palindromic sequences are essential for RecG binding and that single-strand binding proteins and ATP are also needed for RecG to promote transcription, whereas magnesium ion has the opposite effect. The OxyR tetramer preferentially binds to promoters after RecG has generated linear DNA in the presence of ATP; otherwise, the OxyR dimer has higher affinity. This study provides new insights into the mechanism of bacterial transcription by demonstrating that RecG might be required for the induction of the OxyR regulon by unwinding palindromic DNA for transcription. This work describes a novel bacterial transcriptional function by RecG helicase with OxyR and may provide new targets for controlling Pseudomonas species pathogen.
