The accuracy of codon recognition by polypeptide release factors
The accuracy of codon recognition by polypeptide release factors
复制标题
DOI：
10.1073/pnas.030541097
复制
发表时间：
2000-02-29
影响因子：
11.1
通讯作者：
Ehrenberg, M
中科院分区：
文献类型：
--
作者：
Freistroffer, DV;Kwiatkowski, M;Ehrenberg, M
测定了蛋白质释放因子（RFs）识别mRNA中单个终止密码子的精确度，并与tRNA解码有义密码子的精确度进行了比较。利用大肠杆菌体外蛋白质合成纯化系统，研究了RF 1和RF 2在有或无RF 3时终止密码子的精确度，测量在通过单个突变而不同于三个终止密码子中的任一个的所有有义密码子处的因子依赖性终止的效率，并与在三个终止密码子处的终止效率进行比较。RF 1和RF 2以3至大于6个数量级区别与终止密码子相关的有义密码子。这种高水平的准确性是在没有能量驱动的错误校正（校对）的情况下获得的，与核糖体的密码子依赖性氨基-酰基-tRNA识别相反，两个密码子UAU和UGG突出为RF依赖性过早终止的热点。
The precision with which individual termination codons in mRNA are recognized by protein release factors (RFs) has been measured and compared with the decoding of sense codons by tRNA, An Escherichia coli system for protein synthesis in vitro with purified components was used to study the accuracy of termination by RF1 and RF2 in the presence or absence of RF3, The efficiency of factor-dependent termination at all sense codons differing from any of the three stop codons by a single mutation was measured and compared with the efficiency of termination at the three stop codons. RF1 and RF2 discriminate against sense codons related to stop codons by between 3 and more than 6 orders of magnitude. This high level of accuracy is obtained without energy-driven error correction (proofreading), in contrast to codon-dependent amino-acyl-tRNA recognition by ribosomes, Two codons, UAU and UGG, stand out as hotspots for RF-dependent premature termination.