Molecular basis for the functions of a bacterial MutS2 in DNA repair and recombination.
Molecular basis for the functions of a bacterial MutS2 in DNA repair and recombination.
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细菌MUTS2在DNA修复和重组中的功能的分子基础。
DOI：
10.1016/j.dnarep.2017.07.004
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发表时间：
2017-09
期刊：
影响因子：
3.8
通讯作者：
Maier RJ
中科院分区：
文献类型：
--
作者：
Wang G;Maier RJ
细菌MutS2蛋白由ATP酶、DNA结合和核酸酶活性的功能结构域组成，在DNA重组和修复中发挥作用。在这里，我们观察的机制，产生MutS2表达多样性的人类病原体幽门螺杆菌，并确定一个独特的MutS2结构域负责特异性DNA结合。H.幽门螺杆菌菌株由于含有短序列重复的DNA上游序列的变异而在mutS2表达上不同。基于蛋白质印迹，mutS2在一些菌株中似乎与上游基因共翻译，但在其他菌株（例如UA948）中不发生这种翻译偶联。因此，菌株UA948具有与其Δ mutS2衍生物相似的表型，而在UA948（遗传互补菌株）中的单独基因座处表达MutS2显示出比Δ mutS2更低的突变率和更低的转化频率。纯化了一系列截短的HpMutS2蛋白，并测试了它们结合含8-oxoG的DNA（GO：C）和假日连接结构（HJ）的特异性能力。特异性DNA结合结构域定位于邻近Smr核酸酶结构域的区域，并且它包含含有"KPPKNKFKPPK"基序的30个氨基酸残基。凝胶位移测定和竞争测定支持HpMutS2-C12（含有特异性DNA结合结构域的~12kDa蛋白）的截短形式与HJ或GO：C DNA结合的能力比与正常双链DNA结合的能力大得多。通过研究HpMutS2不同结构域在体内的作用，我们观察到截短的形式不能与Δ mutS2菌株互补，这表明体内需要所有结构域的协调功能。
Bacterial MutS2 proteins, consisting of functional domains for ATPase, DNA-binding, and nuclease activities, play roles in DNA recombination and repair. Here we observe a mechanism for generating MutS2 expression diversity in the human pathogen Helicobacter pylori, and identify a unique MutS2 domain responsible for specific DNA-binding. H. pylori strains differ in mutS2 expression due to variations in the DNA upstream sequence containing short sequence repeats. Based on Western blots, mutS2 in some strains appears to be co-translated with the upstream gene, but in other strains (e.g. UA948) such translational coupling does not occur. Accordingly, strain UA948 had phenotypes similar to its ΔmutS2 derivative, whereas expression of MutS2 at a separate locus in UA948 (the genetically complemented strain) displayed a lower mutation rate and lower transformation frequency than did ΔmutS2. A series of truncated HpMutS2 proteins were purified and tested for their specific abilities to bind 8-oxoG-containing DNA (GO:C) and Holiday Junction structures (HJ). The specific DNA binding domain was localized to an area adjacent to the Smr nuclease domain, and it encompasses 30-amino-acid-residues containing a “KPPKNKFKPPK” motif. Gel shift assays and competition assays supported that a truncated version of HpMutS2-C12 (~12 kDa protein containing the specific DNA-binding domain) has much greater capacity to bind to HJ or GO:C DNA than to normal double stranded DNA. By studying the in vivo roles of the separate domains of HpMutS2, we observed that the truncated versions were unable to complement the ΔmutS2 strain, suggesting the requirement for coordinated function of all the domains in vivo.
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影响因子：
3
作者：
Gui, Wen-Jun;Qu, Qian-Hui;Jiang, Tao
通讯作者：
Jiang, Tao
影响因子：
4.7
作者：
Levin-Karp, Ayelet;Barenholz, Uri;Milo, Ron
通讯作者：
Milo, Ron
DOI：
10.1073/pnas.0337641100
发表时间：
2003-03-04
影响因子：
11.1
作者：
O'Rourke, EJ;Chevalier, C;Radicella, JP
通讯作者：
Radicella, JP
影响因子：
14.9
作者：
Eisen, JA
通讯作者：
Eisen, JA
影响因子：
4.8
作者：
Chaturvedi, R;Cheng, YL;Wilson, KT
通讯作者：
Wilson, KT