近日,，國際著名雜志The Journal of Biological Chemistry刊登了韓國高麗大學(xué)研究人員的最新研究成果“Atp-dependent RecG helicase is required for the transcriptional regulator OxyR function in Pseudomonas species”，文章中,，研究者揭示了在假單胞菌中,，ATP依賴的RecG解旋酶對(duì)于轉(zhuǎn)錄調(diào)節(jié)子OxyR的重要作用,。
oxyR基因和recG解旋酶基因在許多細(xì)菌廣泛存在,，這些細(xì)菌包括致病性的銅綠假單胞菌和惡臭假單胞菌,。對(duì)惡臭假單胞菌的轉(zhuǎn)錄組學(xué)分析結(jié)果顯示,，許多OxyR控制的基因同時(shí)也受ATP依賴的RecG解旋酶的調(diào)節(jié),，而且RecG也可以調(diào)節(jié)許多基因的表達(dá)。
在大腸桿菌和腸炎沙門氏菌中,，OxyR可以調(diào)節(jié)很多涉及抵御過氧化氫誘導(dǎo)的氧化壓力的相關(guān)基因的功能,，OxyR對(duì)于氧化還原物質(zhì)敏感而且可以在過氧化氫存在的情況下產(chǎn)生胞內(nèi)的二硫化物結(jié)合物。
轉(zhuǎn)錄組學(xué)分析結(jié)果顯示,，惡臭假單胞菌的氧化壓力效應(yīng)相關(guān)研究并沒有人報(bào)道,，而且在該菌種OxyR并沒有定論，具有DNA修復(fù)功能的RecG在氧化壓力的條件下已經(jīng)進(jìn)行了相關(guān)的研究,，但是RecG和OxyR之間的聯(lián)系卻并不清楚,。
在這項(xiàng)研究中，研究者通過研究表明,，RecG可以直接結(jié)合到OxyR結(jié)合位點(diǎn)的回文序列,，而且RecG對(duì)于OxyR介導(dǎo)的抵御氧化壓力的效應(yīng)激活必不可少。RecG也可以影響許多促進(jìn)產(chǎn)生回文序列特征的基因的表達(dá),。研究者Woojun Park最后表示,，RecG同時(shí)需要鎂離子和ATP來維持其功能。本研究中,，研究者發(fā)現(xiàn)了RecG的一個(gè)新的機(jī)制,，為科學(xué)家研究細(xì)菌的轉(zhuǎn)錄調(diào)節(jié)機(jī)制提供了新的見解。（生物谷Bioon.com）
編譯者：T.Shen
doi:10.1074/jbc.M112.356964
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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.
