O'Connor Michael
School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.
Biochim Biophys Acta. 2003 Oct 20;1630(1):41-6. doi: 10.1016/j.bbaexp.2003.09.002.
Movement of tRNA and mRNA through the ribosome is coupled. However, selection for suppression of a -1 frameshift mutation in Escherichia coli has yielded a class of mutant tRNAs that can violate this mechanism and "hop" or disengage from their cognate codons and re-pair downstream in the mRNA. Previously described tRNA mutants of this class included those with insertions in the anticodon of tRNA(Val)1. This report describes further tRNA(Val)1 alterations that enhance hopping; these include a novel insertion in the anticodon loop, base substitutions in the anticodon stem and a base deletion in the variable loop. These results indicate that several different features of a tRNA are important for maintaining stable codon-anticodon interactions and coupled movement of tRNA and mRNA during the elongation phase of protein synthesis.
转运RNA（tRNA）和信使RNA（mRNA）在核糖体中的移动是相互关联的。然而，通过筛选大肠杆菌中-1移码突变的抑制子，得到了一类突变tRNA，它们能够违反这种机制，“跳跃”或从其同源密码子上脱离，并在mRNA下游重新配对。此前描述的这类tRNA突变体包括在tRNA(Val)1反密码子中存在插入的突变体。本报告描述了进一步增强跳跃能力的tRNA(Val)1改变；这些改变包括反密码子环中的一个新插入、反密码子茎中的碱基替换以及可变环中的一个碱基缺失。这些结果表明，tRNA的几个不同特征对于在蛋白质合成延伸阶段维持稳定的密码子-反密码子相互作用以及tRNA和mRNA的协同移动很重要。
