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锤头结构Ribozyme切割底物时的催化结构包括3个螺旋区和中间10核苷酸的单链区(编号为3～9,12～14,在我们过去文章中称3个双链区为茎区,现根据一些科学家的建议改称为螺旋区.我们原称的茎Ⅰ现称螺旋Ⅲ,原茎Ⅲ现称螺旋Ⅰ,原茎Ⅱ称螺旋Ⅱ).在我们实验室进行的机制研究表明3个螺旋区碱基配对的强弱以及螺旋的构象可影响反应的最适温度和切割效率.将螺旋Ⅰ和/或螺旋Ⅲ的RNA·RNA配对改为RNA·DNA(或DNA·DNA)配对既减弱了Ribozyme与底物的相互作用又改变了螺旋的构象,使反应的最适温度与切割效率都降低很多,有的甚至几乎看不到切割活性.将螺旋Ⅱ的RNA·RNA配对改为DNA·RNA配对只影响螺旋Ⅱ的构象而不影响Ribozyme与底物的相互作用,结果也使反应的最适温度和切割效率降低,但影响较小.为提高Ribozyme稳定性又不影响或少影响它的切割效率,我们研究了2’-O-甲基化对Ribozyme活性的影响.
Hammerhead structure The catalytic structure of the Ribozyme upon cleavage of the substrate consists of three helix regions and a single-stranded 10-nucleotide intermediate region (numbered 3 to 9, 12 to 14, in our previous article, 3 double stranded regions as stem District, now based on the advice of some scientists renamed the spiral zone.We formerly called the stem Ⅰ is now called the spiral Ⅲ, the original stem Ⅲ is called the spiral Ⅰ, the original II called helix Ⅱ) .Study in our laboratory mechanism showed that 3 The strength of base-pairing and the conformation of the helix can influence the optimal reaction temperature and the efficiency of cleavage.The RNA · RNA pair of helix Ⅰ and / or helix Ⅲ is changed to RNA · DNA (or DNA · DNA) Weakened the interaction between Ribozyme and the substrate and changed the conformation of the helix, which reduced the optimum temperature and the cutting efficiency of the reaction, and even almost did not show the cleavage activity. • RNA pairing affects only the conformation of helix II without affecting the interaction of Ribozyme with the substrate and as a result decreases the optimum temperature and cut efficiency of the reaction but with less impact.To improve the stability of Ribozyme without affecting or minimizing it The efficiency of cleavage, we studied 2’-O-methylation on Ri Effect of bozyme activity.