Understanding the Sequence Specificity of tRNA Binding to Elongation Factor Tu using tRNA Mutagenesis

作者：Schrader Jared M; Chapman Stephen J; Uhlenbeck Olke C^*

来源：Journal of Molecular Biology, 2009, 386(5): 1255-1264.

DOI：10.1016/j.jmb.2009.01.021

• EF-Tu
• tRNA mutagenesis
• tRNA protein interaction
• T stem
• thermodynamic compensation

Measuring the binding affinities of 42 single-base-pair mutants in the acceptor and T Psi C stems of Saccharomyces cerevisiae tRNA(Phe) to Thermus thermophilus elongation factor Tu (EF-Tu) revealed that much of the specificity for tRNA occurs at the 49-65, 50-64, and 51-63 base pairs. Introducing the same mutations at the three positions into Escherichia coli tRNA(CAG)(Leu) resulted in similar changes in binding affinity. Swapping the three pairs from several E. coli tRNAs into yeast tRNA(Phe) resulted in chimeras with EF-Tu binding affinities similar to those for the donor tRNA. Finally, analysis of double- and triple-base-pair mutants of tRNA(Phe) showed that the thermodynamic contributions at the three sites are additive, permitting reasonably accurate prediction of the EF-Tu binding affinity for all E. coli tRNAs. Thus, it appears that the thermodynamic contributions of three base pairs in the TIP C stem primarily account for tRNA binding specificity to EF-Tu.

• 出版日期2009-3-13
• 单位西北大学