Xie Ping
Key Laboratory of Soft Matter Physics and Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Math Biosci. 2014 Mar;249:44-51. doi: 10.1016/j.mbs.2014.01.008. Epub 2014 Feb 4.
It has been well characterized that the amino acid starvation can induce +1 frameshifting. However, how the +1 frameshifting occurs has not been fully understood. Here, taking Escherichia coli RF2 programmed frameshifting as an example we present systematical analysis of the +1 frameshifting that could occur during every state-transition step in elongation phase of protein synthesis, showing that the +1 frameshifting can occur only during the period after deacylated tRNA dissociation from the posttranslocation state and before the recognition of the next "hungry" codon. The +1 frameshifting efficiency is theoretically studied, with the simple analytical solutions showing that the high efficiency is almost solely due to the occurrence of ribosome pausing which in turn results from the insufficient RF2. The analytical solutions also provide a consistent explanation of a lot of independent experimental data.
氨基酸饥饿可诱导 +1 移码，这一点已得到充分表征。然而，+1 移码是如何发生的尚未完全清楚。在此，以大肠杆菌 RF2 程序性移码为例，我们对蛋白质合成延伸阶段每个状态转换步骤中可能发生的 +1 移码进行了系统分析，结果表明 +1 移码仅发生在脱酰基 tRNA 从转位后状态解离之后以及识别下一个“饥饿”密码子之前的时间段。对 +1 移码效率进行了理论研究，简单的解析解表明，高效率几乎完全是由于核糖体暂停的发生，而核糖体暂停又是由 RF2 不足导致的。这些解析解还对许多独立的实验数据提供了一致的解释。
