Mechanisms of coupling between DNA recognition specificity and catalysis in EcoRI endonuclease
Mechanisms of coupling between DNA recognition specificity and catalysis in EcoRI endonuclease
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DOI：
10.1016/j.str.2004.07.016
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发表时间：
2004-10-01
期刊：
影响因子：
5.7
通讯作者：
Jen-Jacobson, L
中科院分区：
文献类型：
--
作者：
Kurpiewski, MR;Engler, LE;Jen-Jacobson, L
结合到DNA上的特定位点的蛋白质通常这样做，以便在结合到识别位点时进行催化或特定的蛋白质-蛋白质相互作用。如果这第二个功能与正确的DNA位点识别偶联，则功能特异性增强。为了分析EcoRI核酸内切酶中识别和催化之间耦合的结构和能量基础，我们研究了在易断裂的磷酸GpAATTC或相邻的磷酸GApATTC处的立体特异性硫代磷酸酯（P-S）或甲基膦酸酯（P-Me）取代，并结合Mg 2+的催化中心的分子动力学模拟。结果表明，在催化的个人磷酰氧和DNA畸变的作用，并建议在复杂的“串扰环”的夫妇识别催化和夫妇的两个催化位点彼此。
Proteins that bind to specific sites on DNA often do so in order to carry out catalysis or specific protein-protein interaction while bound to the recognition site. Functional specificity is enhanced if this second function is coupled to correct DNA site recognition. To analyze the structural and energetic basis of coupling between recognition and catalysis in EcoRI endonuclease, we have studied stereospecific phosphorothioate (P-S) or methylphosphonate (P-Me) substitutions at the scissile phosphate GpAATTC or at the adjacent phosphate GApATTC in combination with molecular-dynamics simulations of the catalytic center with bound Mg2+. The results show the roles in catalysis of individual phosphoryl oxygens and of DNA distortion and suggest that a "crosstalk ring" in the complex couples recognition to catalysis and couples the two catalytic sites to each other.