The effect of base mismatches in the substrate recognition helices of hammerhead ribozymes on binding and catalysis.
The effect of base mismatches in the substrate recognition helices of hammerhead ribozymes on binding and catalysis.
复制标题
锤头核酶底物识别螺旋中碱基错配对结合和催化的影响。
DOI：
10.1093/nar/23.12.2092
复制
发表时间：
1995
影响因子：
14.9
通讯作者：
Uhlenbeck,OC
中科院分区：
文献类型：
--
作者：
Werner,M;Uhlenbeck,OC
锤头核酶区分匹配和不匹配底物的能力是用两种不同的底物识别螺旋长度和序列的动力学定义的核酶来评估的。螺旋I最内层碱基对的错配会影响化学裂解步骤k2，而更多的远端错配则不会产生这种影响。相反，螺旋III最内层的四个碱基对中的任何一个错配都会影响k2。Chase实验表明，不匹配也使底物解离率增加了至少20-100倍，正如RNA螺旋稳定性所预期的那样。
The ability of the hammerhead ribozyme to distinguish between matched and mismatched substrates was evaluated using two kinetically defined ribozymes that differed in the length and sequence of the substrate recognition helices. A mismatch In the Innermost base pair of helix I affected k2, the chemical cleavage step, while more distal mismatches had no such effect In contrast, mismatches in any of the four innermost base pairs of helix III affected k2. Chase experiments indicated that mismatches also increased the rate of substrate dissociation by at least 20-100-fold, as expected from the stabilities of RNA helices.