限制性核酸内切酶与DNA相互作用研究进展

Progress on the Interaction of Restriction Endonuclease and DNA

蛋白质对ＤＮＡ识别的模体中，除了锌指结构、螺旋—转角—螺旋、亮氨酸拉链和β带外，近年来发现，Ⅱ型限制性内切酶与ＤＮＡ作用的模体有许多特别之处。通过对ＥｃｏＲＩ、ＢａｍＨＩ、ＥｃｏＲＶ等与ＤＮＡ复合物的空间构象、一级结构分析，发现酶分子存在催化性裂缝，并且氨基端形成臂结构包绕ＤＮＡ；同时ＤＮＡ发生构象变化、螺旋扭结。这些有趣的结构有利于酶对底物的特异性结合和催化作用。

The motif of interaction between type-Ⅱ restriction endonuclease and DNA is found to be different from zinc-finger, helix-turn-helix, leucine-zipper and β-ribbon in protein recognizing DNA in the last few years. The spatial conformation and primary structure of the complexes between DNA and EcoRI, BamHI, EcoRV have been researched. The endonuclease has catalytic clefts and its amino terminal section forms arms which wrap around DNA. Moreover, the conformation of DNA changes and the helices are kinked. These interesting structure are beneficial for enzyme specific binding to substrate and catalytic action.