Kolitz Sarah E, Lorsch Jon R
Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
FEBS Lett. 2010 Jan 21;584(2):396-404. doi: 10.1016/j.febslet.2009.11.047.
The initiator tRNA must serve functions distinct from those of other tRNAs, evading binding to elongation factors and instead binding directly to the ribosomal P site with the aid of initiation factors. It plays a key role in decoding the start codon, setting the frame for translation of the mRNA. Sequence elements and modifications of the initiator tRNA distinguish it from the elongator methionyl tRNA and help it to perform its varied tasks. These identity elements appear to finely tune the structure of the initiator tRNA, and growing evidence suggests that the body of the tRNA is involved in transmitting the signal that the start codon has been found to the rest of the pre-initiation complex.
起始tRNA必须具备与其他tRNA不同的功能，避免与延伸因子结合，而是在起始因子的帮助下直接与核糖体P位点结合。它在解码起始密码子、为mRNA翻译设定读码框方面起着关键作用。起始tRNA的序列元件和修饰使其有别于延伸甲硫氨酰tRNA，并有助于其执行各种任务。这些特征元件似乎精细地调节了起始tRNA的结构，越来越多的证据表明，tRNA的主体参与了将已找到起始密码子的信号传递给起始前复合体的其他部分。
