A re-investigation of the thio effect at the hammerhead cleavage site.
A re-investigation of the thio effect at the hammerhead cleavage site.
复制标题
重新研究锤头裂解位点的硫代效应。
DOI：
10.1093/nar/27.2.479
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发表时间：
1999
影响因子：
14.9
通讯作者：
Uhlenbeck,OC
中科院分区：
文献类型：
--
作者：
Scott,EC;Uhlenbeck,OC
在锤头切割位点引入硫代磷酸酯的效果使用动力学良好表征的锤头进行了研究。在含有镁离子的缓冲液中，RP-硫代磷酸酯异构体裂解速度比SP异构体或未修饰的RNA底物慢2000- 80 000倍。向这些反应中加入低浓度的几种亲硫金属离子，特别是Cd 2+，足以完全恢复RP底物的裂解速率，而不影响全氧或SP底物的裂解速率。因此，一个模型提出的协调的二价金属离子在锤头切割位点的pro-R氧似乎是合理的。
The effect of introducing a phosphorothioate at the hammerhead cleavage site was investigated using a kinetically well-characterized hammerhead. In buffers containing Mg ion, the RP-phosphorothioate isomer cleaved 2000- to 80 000-fold slower than the SPisomer or the unmodified RNA substrate. Addition of low concentrations of several thiophilic metal ions, especially Cd2+, to these reactions is sufficient to fully restore the cleavage rate of the RPsubstrate without affecting cleavage rate of the all-oxygen or SPsubstrate. Thus, a model proposing coordination of a divalent metal ion to the pro-R oxygen at the hammerhead cleavage site appears justified.