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【bio-news】《Cell》:DNA最小转位酶的运行机制
The smallest known DNA transposases are those from the IS200/IS605 family. Here we show how the interplay of protein and DNA activates TnpA, the Helicobacter pylori IS608 transposase, for catalysis.
First, transposon end binding causes a conformational change that aligns catalytically important protein residues within the active site. Subsequent precise cleavage at the left and right ends, the steps that liberate the transposon from its donor site, does not involve a site-specific DNA-binding domain. Rather, cleavage site recognition occurs by complementary base pairing with a TnpA-bound subterminal transposon DNA segment. Thus, the enzyme active site is constructed from elements of both protein and DNA, reminiscent of the interdependence of protein and RNA in the ribosome.
Our structural results explain why the transposon ends are asymmetric and how the transposon selects a target site for integration, and they allow us to propose a molecular model for the entire transposition reaction.
http://www.cell.com/content/article/abstract?uid=PIIS0092867408000469
作者单位
1 Laboratory of Molecular Biology, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
2 Laboratoire de Microbiologie et Génétique Moléculaires Centre, National de la Recherche Scientifique, 118 Route de Narbonne, 31062, Toulouse Cedex, France 我认领该篇文章的编译，若48小时内未能成功编译，请其他战友自由编译。 对不起诸位，这是一篇很深奥的科研文献，没有临时佛脚抱，看的不是很明白，很后悔刚开始的冲动了，教训是：翻译前一定要真正明白内容，不可为了分撕榜：（
Mechanism of IS200/IS605 Family DNA Transposases: Activation and Transposon-Directed Target Site Selection
IS200/IS605 家族DNA转位酶机制：定位靶点选择的激活与转位
The smallest known DNA transposases are those from the IS200/IS605 family. Here we show how the interplay of protein and DNA activates TnpA, the Helicobacter pylori IS608 transposase, for catalysis.
已知最小的DNA转位酶来自IS200/IS605家族。在此，我们技术示范蛋白与DNA活化产物TnpA怎样相互作用，幽门螺杆菌IS608转位酶催化。
First, transposon end binding causes a conformational change that aligns catalytically important protein residues within the active site. Subsequent precise cleavage at the left and right ends, the steps that liberate the transposon from its donor site, does not involve a site-specific DNA-binding domain. Rather, cleavage site recognition occurs by complementary base pairing with a TnpA-bound subterminal transposon DNA segment. Thus, the enzyme active site is constructed from elements of both protein and DNA, reminiscent of the interdependence of protein and RNA in the ribosome.
首先，转位子结束粘附，导致催化酶排列成直线的重要蛋白残基发生构象变化，进入活性中心；随之而来的是左右两边精确的切除，这个步骤使转位子从供体的结合位点释放出来，并不包括位点特异性的DNA结合区域。更准确的是，切割位点通过近端带有TnpA结合DNA片段与互补碱基配对相互识别。至此，酶的活性位点构成了蛋白和DNA单元，暗示了蛋白质与RNA在核糖体上的相互依赖性。
Our structural results explain why the transposon ends are asymmetric and how the transposon selects a target site for integration, and they allow us to propose a molecular model for the entire transposition reaction.
我们的结构结果解释了转位子末端为何不对称以及转位子如何选择靶点整合，并使得我们提出全部转位反应的分子模型。
编译如下：
IS200/IS605 家族DNA转位酶机制：定位靶点选择的激活与转位
已知最小的DNA转位酶来自IS200/IS605家族。在此，我们技术示范蛋白与DNA活化产物TnpA怎样相互作用，幽门螺杆菌IS608转位酶催化。
首先，转位子结束粘附，导致催化酶排列成直线的重要蛋白残基发生构象变化，进入活性中心；随之而来的是左右两边精确的切除，这个步骤使转位子从供体的结合位点释放出来，并不包括位点特异性的DNA结合区域。更准确的是，切割位点通过近端带有TnpA结合DNA片段与互补碱基配对相互识别。至此，酶的活性位点构成了蛋白和DNA单元，暗示了蛋白质与RNA在核糖体上的相互依赖性。
我们的结构结果解释了转位子末端为何不对称以及转位子如何选择靶点整合，并使得我们提出全部转位反应的分子模型。
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作者:admin@医学,生命科学 2011-04-16 17:14
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